This PR fixes a bug where alt-dragging the left or right handles of a
text shape would not produce the correct outcome: the width would double
but the center would change.
This is because the text shape is aspect ratio locked only when dragging
handles other than the left or right, but we didn't have the ability to
differentiate between that. We've had to add that optionality in,
together with a hard-coded override of the normal behavior for text
shapes.
### Change Type
- [x] `sdk` — Changes the tldraw SDK
- [x] `bugfix` — Bug fix
### Test Plan
1. Resize text.
2. Resize text with the alt key held.
- [x] Unit Tests
### Release Notes
- Fixed a bug with resizing text shapes from the left and right while
holding alt.
79ca14454e