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

[lewing]

arcade/src/Microsoft.DotNet.Build.Tasks.Installers/build/wix/wix.targets

Line 46 in dfb902f

<Target Name="_GenerateMsiVersionString">

.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:

• [release/6.0] Tweak workload build to use _GenerateMsiVersionString target runtime#60695
• [release/6.0] Tweak workload build to use _GenerateMsiVersionString target emsdk#89

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

cc @steveisok @joeloff @mmitche

[AraHaan]

That is not the only thing I do not like about the msi gen in arcade:

For starters people outside of the .NET Foundation (me) use the arcade to build msi installers for windows and they incorrectly get stamped with:

• Copyright: Microsoft Corporation

by default instead of their own copyright setting.

Hopefully the macos pkg gen does not have that issue as well too.