[Finishes #74421214] Make students use if blocks

The goal is to make sure that students use if blocks even in places where they could accomplish all goals without (i.e. if I have a purple flower with zero nectar, I still want to make the student check it for nectar).

This change ended up being a little bit more involved than I thought, in large part because I ended up moving some things around from beeItemDrawer to bee.  The interactions between Maze/Bee/BeeItemDrawer are still a little messier than I'd like, but it's hard to make things much better without making Maze more modular.

Do let me know if anything seems unclear