This PR fixes the positions of assets created when multiple assets are
created at once.
### Change Type
- [x] `sdk` — Changes the tldraw SDK
- [x] `bugfix` — Bug fix
### Test Plan
1. Drop / paste multiple images on the canvas.
2. The shapes should be top aligned and positioned next to eachother.
### Release Notes
- Fixes the position of multiple assets when pasted / dropped onto the
canvas.
487b1beb85