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