SYSML2_ — Mappings from the "Common" package

There is a bunch of mapping defined in the "GenericMappings::Common" package. However, they are not used very much in by other mappings while multiple more specific versions of them have been created without a good rationale. Defining reusable mappings is a good idea and could greatly simplify the specification of the transformation by reducing the number of classes it contains... Assuming they are actually used!

I do think it deserves a global review and optimization.

Note that some of those "common" mappings shall be fixed with regard to either their source type, the body condition of some of their rules or both.