Fix default WinUI version for .bat solution generation

[Arlodotexe]

Background

See:

• Default solution generation only including UWP and WASM heads not WASDK #259
• Why do you remove wasdk target when both "uwp, wasdk" are specified in GenerateAllSolution.ps1? #247 (comment)

If you need to work with WinUI 3 / Wasdk instead of our default (uwp), pass the -winui 3 parameter in when generating the solution:

.\tooling\GenerateAllSolution.ps1 -MultiTargets wasdk,wasm,android,ios -Components Media,SettingsControls -winui 3 

The Components and MultiTargets params can be customized as needed for your scenario. Removing these params will generate uwp or wasdk + wasm, depending on the -winui value given.

The use case for the GenerateAllSolution.bat is to provide a double-click option from the file explorer.

Problem

The GenerateAllSolution.bat file doesn't appear to provide a way to use WinUI 3 without knowing how to call the underlying PowerShell script in our tooling instead.

This shouldn't be the case. At minimum, WinUI 3 should be the default, as the Windows App SDK is the recommended framework from Microsoft.

Solution

We need to either:

• Allow choosing between winui 2 and 3 via two separate .bat files
• Change the default winui version when using the bat file to winui 3