Enhance Sprig-Reap's Abilities to Handle Polymorphism

Sprig-Reap was unable to properly identify dependencies and polymorphic-associated classes.  This PR adds some additional intelligence around that logic.

Eli and I paired on this stuff.  We also cleaned up small things here and there.
This is getting kind of hard to follow and to know what it's really testing. Lack of ideas for better suggestions other than less doubles and stubs.