Show name of generic implementation class with mapped classes

[Matthias Schoettle]

Taken out of #321:

When reusing Association, the getAssociated operation is mapped to getAs and returns, for example, ArrayList<|Associated|>. Since |Associated is mapped, we can show the mapped to class.

So what we discussed is that it is not an error, if the operation is not public, because it won't be visible to a reusing concern. However, it should display as ArrayList<B>.

If the operation is public, the class needs to be re-exposed, i.e., the user has to create the class in the model specifically (could also be done through a quickfix).

This issue is just for the name.

[Matthias Schoettle]

Resolves #374: Adds a specialized textual representation for implementation classes from reused concerns if there generic types are mapped (for example when reusing Association). This is currently only done for Operation's return type and Parameter's type.

→ <<cset 0b9fafe47c4c>>

[Matthias Schoettle]

References #374: Fixes bug introduced in commit 0b9fafe that added the actual name of a type only in the else branch instead of in all cases.

→ <<cset 10510f7b7461>>