This PR fixes a bug in firefox where the pointer can get stuck down
while pressing the control key.
It achieves this by taking a previous fix (specifically for
`useShapeEvents`), and it applies the fix at a deeper level (within
`app.dispatch`).
## Before
## After
### Change Type
- [x] `patch` — Bug Fix
### Test Plan
1. Use firefox.
2. On the canvas... pointer down (to start a selection box).
3. Control key down.
4. Pointer up.
5. Make sure that that the selection box is gone.
^ Repeat the above for:
Pointer down on a shape.
Pointer down on a handle.
### Release Notes
- [Firefox] Fixed a bug where the pointer could get stuck down when the
control key is held down.
Lu Wilson