Use asNominalTypeDecl more:

• to resolve methods and variables declared in extensions correctly. We've had models fail in both tests and real world query runs in the past because they were looking for something in a particular named type declaration, but that thing was actually in an extension of it.
• to avoid needing special case disjuncts to do so.

Some of these changes could affect results, so I'll do a DCA run to be safe.