This PR:
- improves the logic for computing `renderingShapes`
- improves the handling of side effects related to cropping
We might use the same side effect logic to edit / re-edit shapes, though
this may be more complicated with inputs that steal focus.
### Change Type
- [x] `major` — Breaking change
### Test Plan
1. Crop an image
2. Change the crop
3. Stop cropping
4. Undo — you should be cropping again!
5. Undo until you're not cropping anymore
6. Redo until you're cropping again
7. etc.
- [x] Unit Tests
eabb0d52f8