We're missing the export for `createShapePropsMigrationIds`, so lets add
it. This also fixes some other bits that were used in examples but not
exported properly from tldraw.
### Change Type
- [x] `sdk` — Changes the tldraw SDK
- [x] `bugfix` — Bug fix
### Release Notes
- Expose `createShapePropsMigrationIds`, `defaultEditorAssetUrls`,
`PORTRAIT_BREAKPOINT`, `useDefaultColorTheme`, & `getPerfectDashProps`