How to set a click event function for each mesh in scene?

### 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

Hello everyone and thanks in advance for the possible help you can give me.

I have a list of ply objects which I currently draw into a scene using the draw function providing a list of dictionaries with each mesh, its material and a name (the material I use is MaterialRecord just to be able to change the alpha channel value to control transparency). This script is very simple but I would like to enhance the capabilities of it. Each of the ply objects has numerical values as sensor values as this is for an industrial application. I would like to be able to clik on each of the meshes and trigger a function with it that gives me some numerical information in the 3D visualizer as a text panel or by opening a new window with this information. Is there any possibility I can do this by using mouse clicking and not by binding keyboard letters to each of the meshes with the draw_geometries_with_key_callbacks?

Thank you in advance, any help is appreciated!