This PR fixes a bug where pasted tabs didn't get converted to spaces.
Fixes#1387
We manually convert tabs to spaces when pressing the tab key. But we
were missing cases where you pasted tabs.
This may or may not be needed with @SomeHats's incoming text change!
<img width="825" alt="Screenshot 2023-05-16 at 12 35 37"
src="https://github.com/tldraw/tldraw/assets/15892272/239771d5-ab65-41e1-9215-60af3fab5c8b">
<img width="763" alt="Screenshot 2023-05-16 at 12 25 03"
src="https://github.com/tldraw/tldraw/assets/15892272/307a6c3a-9f8f-44a8-9e66-a694b92c5067">
### Change Type
- [x] `patch` — Bug Fix
### Test Plan
1. Copy a tab character: ` `
2. Make a text shape.
3. Paste the tab character.
4. Make sure that it has been converted into 2 spaces.
- [ ] Unit Tests
- [ ] Webdriver tests
### Release Notes
- Fixed a bug where pasted tabs wouldn't get converted into spaces.
d198bb3645