Wix _GenerateMsiVersionString should be usable with the signed wix packages for workloads

https://github.com/dotnet/arcade/blob/dfb902f38e7c68d8cd83d53f32ea174e8f3a310a/src/Microsoft.DotNet.Build.Tasks.Installers/build/wix/wix.targets#L46

.NET workload manifests need a way to generate correct msi versions but can't easily use the current _GenerateMsiVersionString wix target so we've had to duplicate the target in:
- https://github.com/dotnet/runtime/pull/60695
- https://github.com/dotnet/emsdk/pull/89

We'd like to get rid of that duplication and use shared code

cc @steveisok @joeloff @mmitche