Gui overlapping

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### Describe the issue


### Steps to reproduce the bug

Run the example/Draw, and if the window size is small, the GUI has scroll area. When picking different labels, the overlapping of gui will appears.

### Error message

_No response_

### Expected behavior

_No response_

### Open3D, Python and System information

```markdown
- Operating system: Ubuntu 22.04
- Open3D version: b7f9f3ae619b8dddda9b3118d69785e30d33194a
- System architecture: x86
- How did you install Open3D?: build from source
```

### Additional information

_No response_