chore(editor): adjust min width of edgeless note (#10153)

Close [BS-2499](https://linear.app/affine-design/issue/BS-2499/所有notes最小宽度调整为218px)

### What changes
- adjusted min width of edgeless note
  - placeholder show ellipsis in min edgeless note
- refactored somes button of `change-note-button.ts` with `isPageBlock`

blocksuite/affine/block-note/src/index.ts

@@ -6,3 +6,4 @@ export * from './note-block';
 export * from './note-edgeless-block';
 export * from './note-service';
 export * from './note-spec';
+export { isPageBlock } from './utils';