[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
Ah, right! Misread this, maybe pull `this.isFlower(row, col) && !this.isRedFlower(row, col)` into an `isPurpleFlower` helper or variable