Part of Project clean-up #529 (#587)

* moved files and fixed XCT solution

* fixed Markup solutions

* Renaming, tidying

- More renaming of files and folders to be more consistent
- Added UnitTest project to Xamarin.CommunityToolkit solution
- Removed unused Support.md
- Fixed path to csproj in build yaml to fix the build

* Update azure-pipelines.yml

* Update Xamarin.CommunityToolkit.UnitTests.csproj

Co-authored-by: Gerald Versluis <gerald@verslu.is>

Author: pictos

Support.md

@@ -3,9 +3,9 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 16
 VisualStudioVersion = 16.0.30413.136
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Xamarin.CommunityToolkit.Markup", "Xamarin.CommunityToolkit.Markup\Xamarin.CommunityToolkit.Markup.csproj", "{AB7BC9C1-E0E5-41F0-A1B9-9AEDD3A3C91A}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Xamarin.CommunityToolkit.Markup", "src\Markup\Xamarin.CommunityToolkit.Markup\Xamarin.CommunityToolkit.Markup.csproj", "{AB7BC9C1-E0E5-41F0-A1B9-9AEDD3A3C91A}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Xamarin.CommunityToolkit.Markup.UnitTests", "Xamarin.CommunityToolkit.Markup.UnitTests\Xamarin.CommunityToolkit.Markup.UnitTests.csproj", "{43798DE5-81F4-4C31-8BB2-AEF46F6732AB}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Xamarin.CommunityToolkit.Markup.UnitTests", "src\Markup\Xamarin.CommunityToolkit.Markup.UnitTests\Xamarin.CommunityToolkit.Markup.UnitTests.csproj", "{43798DE5-81F4-4C31-8BB2-AEF46F6732AB}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution