* Remove NuGet.Client source build patches
After the latest flow from nuget, I am fairly sure after examining and attempting to apply these patches that they all are no longer necessary. There are some slight diffs (they don't all apply as no-ops), but the code in question appears to be okay on inspection.
* Port missing parts of the patch.
* Don't remove necessary files in Roslyn patch.
Co-authored-by: Chris Rummel <crummel@microsoft.com>
