How to select points in point cloud by mouse dragging and undo the selecting action?

### 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).

### My Question

Thank you for your work.

I have a question about point selection in point clouds.
By using VisualizerWithEditing, I can select one point by mouse click and undo it.

How to pick points by mouse dragging?
I manage to find the similar answer by using VisualizerWithVertexSelection.
However, this method has lots of issues and quite unstable compared to VisualizerWithEditing method(select one point by click).

Issue lists
1. It is only working when pressing shift and point colors are changed.
2. Added geometry can be moved, not fixed.
3. Undo selecting only works by clicking not dragging.

Is there anybody knows the answers?