Add support for requesting WinUI 0 (non-WinUI) components be build. For use by packaging CI matrix.

[Arlodotexe]

This PR:

• Introduces the concept of "WinUI 0" as possible parameter in our Build-Toolkit-Components.ps1 script, indicating that non-WinUI projects should be built.
• Fixes the "skip building component" logic for WinUI 2 and 3 projects
• Allows consuming repositories (Labs, mainline WCT) to build and package WinUI 0, 2 and 3 components concurrently in CI without race conditions or improperly skipped components.

Prerequisite PR: CommunityToolkit/Tooling-Windows-Submodule#258

[Arlodotexe]

This is failing because the mainline WCT doesn't have any components that are netstandard-only. For now, let's close the PR but keep the branch so we can re-open and close if we get components that are ns2.0 only.