Initial implementation of Sandworms (WIP; Need help with audio and animations)

Using Mailaender's code as basis, this is my implementation of the sandworm behavior. It is still WIP, but you can get an idea of how it looks from the shellmap.
Not sure how to handle this. I don't see any use case for Swallow/SwallowActor besides the sandworms (so there should not be a case where this throws). But maybe CanAttackAtLocation() should not be in the Sandworm class?