[827616] Add ASP.NET Core Publish To Folder unit tests

[Semptra]

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/827616

Added PublishToFolder unit test, refactored Publish method (cannot test it before - there was a lot of logic dependent on IdeApp).

[Semptra]

@rodrmoya for some reason publishing for Windows ARM64 fails (only with .NET Core 3.0):

PublishToFolder("aspnetcore-empty-30","publish --configuration Release --self-contained --runtime win-arm64 --output bin/release-22self-contained-win-arm64")

Publish to Folder command exit code must be 0
Expected: 0
But was:  1