Unified Build Controls

[mmitche]

Description

Update the unified build control set to remove source-build specificity and enable Unified Build

General Work

• [x] https://github.com/dotnet/source-build/issues/2974
• [x] #3932
• [x] #3937
• [x] #3938
• [x] #3939
• [x] #3940
• [x] #3941
• [x] #3942
• [x] #3943
• [x] #3944
• [x] #3945
• [x] #3946
• [x] #3947
• [x] #3961
• [x] #3948
• [ ] #3949
• [ ] #3950
• [ ] #3951
• [x] #4008
• [ ] #4182
• [ ] https://github.com/dotnet/arcade/issues/14768

T-Shirt Size: Large

[dotnet-issue-labeler[bot]]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[mmitche]

/cc @MichaelSimons @richlander @crummel

[mmitche]

Part of #2911

[mmitche]

Once aspnetcore goes in, this will be officially back in the "Blocked" column.

[mmitche]

Blocked on net8 arcade moves.