* Update build.cmd to install .NET Core into $repoRoot/.dotnet instead of $repoRoot/.dotnet/x64
* Move restore sources from build/sources.props into eng/Versions.props (following arcade conventions)
* Remove usages of RuntimeFrameworkVersion in tests and build
* Update Blazor VSIX to use Arcade VSIX tools
* Rename Common.Tests to IIS.Common.TestLib and make it a test asset
* Remove custom versions props for ANCM installer code
* Remove duplicate references to xunit and remove usages of IsTestProject
* Remove duplicate references to Internal.AspNetCore.Analyzers
* Import Arcade.Sdk props and targets and remove custom versioning props
* Remove references to Internal.AspNetCore.Sdk
* Rename PackageLicenseType => PackageLicenseExpression
* Remove dependency on tasks in Internal.AspNetCore.Sdk, add ref to Internal.AspNetCore.BuildTasks as a temporary workaround
* Use Arcade's nuspec support
* Rename SignalR.Client.FunctionalTests to SignalR.Client.FunctionalTestApp
* Fixes for changes to property evaluation order
* Update BaseLineGenerator to netcoreapp3.0
* React to changes in evaluation order in RPM files and quirks in using <Exec> instead of <Run>
* Update Microsoft.Extensions.ApiDescription.Server to react to changes in Arcade packaging
* Workaround aspnet/AspNetCore#11009

The Arcade SDK requires that the obj/ and bin/ folders be placed in the top-level artifacts/ folder of the repo. Although this PR does not complete our Arcade convergence, this is a step towards updating our repo to build with the Arcade SDK.

Changes:
* Set output path for build to artifacts/bin/$(ProjectName)/ 
* Set intermediate output path for build to artifacts/obj/$(ProjectName)/
* Cleanup .gitignore files (remove duplication between repo-root and tested gitignore files)
* Add code check which looks for project files that share the same name (could cause issues)
* Rename project files to have unique names (avoid race condition of build output)
* Update all locations which were hard-coded to expect bin/ and obj/ in the project directory
* Add overrides for tests which still assert test binaries exist in a given location relative to the source code

Preparing to adopt the Arcade SDK, which uses the shorter variable name instead

* Add build for linux-musl-arm64

* Remove redundant apk installs

* Enable Pubternal API checks

* Use pragma

* Convert to pragma

* Test fix

* Remove extra restore dependencies

* Deprecate the Microsoft.AspNetCore.App metapackage in favor of targeting and runtime packs
* Stop producing Microsoft.AspNetCore.App, and runtime.$(rid).Microsoft.AspNetCore.App
* Generate the shared framework without using 'NuGet' restore
* Stop producing intermediate packages for shared-framework only assemblies
* Put the platform manifest into the targeting pack (data/Microsoft.AspNetCore.App.PlatformManifest.txt)
* Create well-known, shared intermediate directories that installers can use to bundle content

This creates 3 new build outputs:

* aspnetcore-targeting-pack-$(version).tar.gz
* aspnetcore-targeting-pack-$(version)-linux-x64.deb
* aspnetcore-targeting-pack-$(version)-linux-x64.rpm

Other changes:
* Make RPM packaging consistent with other installers. Vendor == Microsoft Corporation
* Add shared properties for building the targeting pack (or not building it in a servicing build)

Changes:

* Make Visual Studio 2019 a prerequisite for building this repo
* Update .sln files
* Update Windows SDK to 17134
* Update developer docs
* Disable ANCM tests
* Update to .NET Core SDK 3.0 Preview 2
* Use Microsoft.NET.Sdk.Razor as a package consistently accross the repo
* React to changes in metadata from Microsoft.NETCore.App
* React to changes in .NET Core SDK
* Attempt to workaround CodeCheck.ps1 failure which doesn't repro locally or on different agents. Possibly due to differences in the version of the PowerShell task?
* Remove dead YML file
* Rename usages of win7-{x64,x86} to win-{x64,x86}
* Update KoreBuild to 3.0.0-build-20190219.1

Part of #6501 

This adds a new Windows installer for the targeting pack. It places *.dll and *.xml (docs) in `[DOTNETHOME]\packs\Microsoft.AspNetCore.App.Ref\$(version)\ref\netcoreapp3.0`.

Outputs:
* aspnetcore-targeting-pack-$(version).zip
* aspnetcore-targeting-pack-$(version)-win-x64.exe (defaults to C:\Program Files\dotnet)
* aspnetcore-targeting-pack-$(version)-win-x86.exe (defaults to C:\Program Files (x86)\dotnet)

These all include the same files. These are meant to be bundled in the .NET Core SDK installer, but can be launched directly too.

Replace custom targets for generating assembly attributes and source control info by using SDK features (#7504)

Changes:
* Add support for a property, `IsAspNetCoreApp`, in the .csproj file of assemblies which are part of the shared framework. 
* Remove unused dependencies
* Remove reference which have become part of 'netcoreapp3.0'

Install the .NET Core SDK into the repo root instead of UserProfile and 'install' copy of AspNetCore shared framework (#7293)

This is required to workaround several limitations in the way the .NET Core SDK finds shared frameworks and targeting packs. It allow tests to use shared frameworks and targeting packs.

It also matches the patterns established in other aspnet and dotnet repos. This should reduce the friction required to adopt Arcade SDK.

## Changes

* This moves the default location of the .NET Core SDK installation into `$repoRoot/.dotnet`. This location was already in use for CI builds. 
* Update the build step for Microsoft.AspNetCore.App to install the shared framework into the local copy of the .NET Core SDK

## Recommendations

* Use the "startvs.cmd" script to launch Visual Studio. This will set required environment variables to make VS happier than if you just double click the .sln file.
* Use "activate.sh/ps1" if you want to run `dotnet build`, `dotnet test` and other dotnet commands. These will set required environment variables, including PATH.
* I recommend removing %USERPROFILE%/.dotnet to your PATH variable if you had added it manually before. This will no longer match what build tools will install.
* `git clean -xfd -e .dotnet/` preserves the folder so you don’t have to re-download the SDK again.

Add new build.cmd/sh options for suppressing restore, NodeJS, setting target arch and OS name, and more (#7137)

Add new command line parameters for working with the project:

* `-NoBuild`, `-NoRestore` - these already existed, but users found it hard to discover this powershell syntax: '-build:$false'
* `-Arch`/`--arch` - set the target CPU architecture to build. Defaults to x64
* `--os-name` - on non-Windows builds, manually specify if the build should target Alpine. generic Linux, or MacOS
* Rename flags used to build specific project types. The pattern now is `--build-$(group)` or `--no-build-$(group)` (In PowerShell its `-Build$(Group)` or `-NoBuild$(Group). Example: -NoBuildJava

Changes to build definitions:
* Update the ci build definition to build all supported architectures
* Support publishing multiple artifacts per job

Other changes:
* `-NoBuild` implies `-NoRestore`
* Add new properties, `TargetArchitecture`, `TargetOsName`, and `TargetRuntimeIdentifier`
* Replace usages of `SharedFxRid` with these new properties
* To make `--no-build-nodejs` actually work, replaced Components.Browser.JS.csproj with Components.Browser.JS.npmproj
* Fix errors when building for win-arm on a clean machine
* Fix a few other project errors, like using the wrong syntax for DefaultItemExcludes, or using the wrong Platform value for x86

Changes:

* Remove obsolete targets which are unnecessary now that this repo no longer builds git submodules in a separate build process
* Remove the need for static analysis of 'ArtifactInfo' items
* Simplify how the code signing task is configured
* Remove unused repo tasks
* Remove duplicate lists of external dependencies and packages to be produced
* Remove obsolete build definition
* Remove obsolete build script parameters
* Add VisualStudioSetupOutputPath

Changes:
* IsProductPackage => IsShippingPackage
* artifacts/$config/packages => artifacts/packages/$config
* packages/product => packages/Shipping
* packages/internal => packages/NonShipping
* Renamed MSBuild properties used for output folders
* Update build tools to use 2 spaces in global.json

Part of #4246 

Changes:
* Update source code layout to follow the new conventions for this repo
* Update project files to use `<Reference>`
* Update targets to build NPM packages
* Update BuildTools to support custom 'restore' and 'test' targets

.NET Core 2.0 reached EOL last year. This removes multi-targeting our test projects and test assets to only use .NET Core 2.1 and .NET Framework 4.6.1.

Fix broken tests and VS solutions caused by source code reorganization and other build infra cleanup

Changes:
* Fix broken tests and VS solutions caused by source code reorganization
* Add a check to validate generated code and solutions on PRs
* backport some source code reorg to src/Identity
* Fix startvs.cmd if you've already run build.ps1
* Add PR checks for tests on Linux/macOS
* Skip broken Nginx tests
* Add conditions to skip IIS tests on non-Windows platforms

Fix VS errors about repotasks when repotasks have not been built, and update documentation to indicate that VS users should invoke restore.cmd first (#6295)

Follow-up to #6078

This should solve race conditions in restoring .wixproj files.

Co-authored-by: Nate McMaster <natemcmaster@users.noreply.github.com>
Co-authored-by: Justin Kotalik <jkotalik@users.noreply.github.com>

This simplifies the way that we publish files to our network drop share.

Changes:
* Instead of explicitly listing every file that needs to publish, use directories to classify packages and artifacts into different categories.
* Add documentation for the expected layout of artifacts/
* Remove the need for static analysis to determine which packages go to which project
* Add the MSBuild property "IsProductPackage" to .csproj files which ship as a package to NuGet.org.

As a result of removing Razor's VS projects and upgrading all projects to netcoreapp3.0, we no longer need dependency variable for .NET Core 1.x and 2.x and Visual Studio packages.

Changes:
* Remove 'StandardTestTfm'
* Remove variables for .NET Core 1.0, 1.1, 2.0, 2.1, and 2.2
* Remove VSIX variables
* Stop generating 'branding.props' - this hasn't been used in a while and is no longer needed

Changes:
* Ensure IIS managed and pkg projects build after the native projects
* Update projects to build test
* Update CI checks to build on macOS and Linux
* Use package baselines to manage ANCM packages

Prior to reorganization, this source code was found in https://github.com/aspnet/Identity/tree/4a717c85635671e04c8691fe3c125a77ee46d32a

Prior to reorganization, this source code was found in https://github.com/aspnet/Identity/tree/4b3d8e5106158fb29da33c8e14134ed168a5e880

Prior to reorganization, this source code was found in https://github.com/aspnet/Identity/tree/fa3cfd08eb6af819adc5fef2d9b603638c4b4b3b

Prior to reorganization, this source code was found in https://github.com/aspnet/Localization/tree/0bcac31dd705fb9db60723f5d7eaeffb728358f5