Consider adding Roslyn component multi-targeting to templates

[Youssef1313]

trafficstars

It would be very useful if the default templates have the enhanced analyzers/dotnet directory layout that allows multi-targeting roslyn components. See https://github.com/dotnet/sdk/pull/20793

[Youssef1313]

https://github.com/YairHalberstadt/stronginject/commit/40c27214a3405a3e8f3a2cbd83aed27566cbc797 for an example where this was done.

[sharwell]

This should be implemented such that the generated package project automatically places assemblies into the correct version folder based on the references present in the project. For example, this means a user who only changes the Version value of a project reference from 4.0.1 to 4.1.0 will see the assemblies move in the package from roslyn4.0 to roslyn4.1.