Compare assembly identities in the asset comparison tooling

[ViktorHofer]

The assembly identity consists of AssemblyName + AssemblyVersion + Culture + PublicKeyToken, i.e.:

Microsoft.VisualStudio.SolutionPersistence, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a

It would be good when comparing packages and containers, to also compare the assembly identities for managed assemblies. That will catch cases where we unintentionally change parts of the identity.

cc @mmitche

[mmitche]

Completed with dotnet/sdk#47700 and previous changes to this tool.