crutkas: taking over the body here for creating the work items

Can do now work:

• Upgrade everything to .NET Core/Standard away from .NET Fx. <- Upgrade any .NET Framework area to .NET Core 3 #776
• Eliminate all dependencies that are .NET Fx only. <- Remove all .NET Fx dependencies #8557
• Upgrade everything to .NET 5 <- Upgrade .NET Core 3.1 to .NET 5 #8650
• Runner: the exception handler is relying on x64-specific registers
• Update installer to verify proper processor type for installer
  • don't do ARM installer for x64 user
  • don't do x64 installer for ARM user

Pure ARM64 solution

• WPF ARM64 support <- How about supporting ARM64. dotnet/wpf#1817
• WinForms ARM64 support
• Installer updates
• Get CI to ARM64 solution
• Get Build farm to ARM64

Hybrid solution work (ARM64 where possible, everything else is x86)

• Get solution to work E2E on x86
• Update installer to verify proper processor type for installer
  • warn do x86 installer for x64 user
• Get solution to work in hybrid ARM64/x86