* Restore public API contract on WebAssemblyJSRuntime (#19968)

* Shrink icon-512.png (#19999)

* Use custom DebugProxyHost to initialize DebugProxy config (#19980)

Addresses #19909

* Spruce up WebAssemblyHostEnvironment interface and use (#20008)

* Load .dlls/.wasm/.pdb in parallel with dotnet.*.js. Fixes #18898 (#20029)

* Add BaseAddress property to WebAssemblyHostEnvironment (#20019)

- Adds `BaseAddress` to `IWebAssemblyHostEnvironment`
- Uses unmarshalled APIs to extract application host
- Move NavigationManager initialization to startup code
- Fix subdir mapping in ClientSideHostingTest

Addresses #19910

Co-authored-by: Steve Sanderson <SteveSandersonMS@users.noreply.github.com>
Co-authored-by: Safia Abdalla <safia@safia.rocks>
Co-authored-by: Safia Abdalla <safia@microsoft.com>