Move Microsoft.Maui.Graphics.Xaml.UWP into the Maui repo #8697
Description
This was initially excluded from the merge in #8147 because it was not actually building in that repo.
Based on demand this can be moved here. However, in order to make sure that the code in the repo is actually buildable, we are not moving it right away.
NOTE: UWP is no longer a main development area since WinUI