open source rest of managed WPF assemblies

[stevenbrix]

Open source the rest of the managed assemblies:

1. PresentationUI
2. System.Windows.Presentation
3. System.Windows.Controls.Ribbon
4. System.Printing
5. Themes
   • PresentationFramework.Aero
   • PresentationFramework.Aero2
   • PresentationFramework.AeroLite
   • PresentationFramework.Classic
   • PresentationFramework.Luna
   • PresentationFramework.Royale

The following steps need to be done to ensure this is done right:

1. Add new OSS license headers
2. Scan/clean code using Policheck
3. Verify no IL differences when building in the new repo
4. Validate both dotnet/wpf and dotnet-wpf-int builds correctly consume the nuget packages

[stevenbrix]

Here is the internal PR that removes the code: https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-int/pullrequest/2583?_a=overview

[grubioe]

Reviewed during 8/13 .NET Tactics