Request to add eye-dome lighting (EDL) to visualization

### 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).

### Proposed new feature or change

Certain pointclouds, especially those that capture large natural environments, are difficult to visualize with the current renderer.
Object boundaries are hard to see because of the large amount of points.

Using eye-dome lighting (EDL) improves the visualization massively, so it would be very nice to have this as an available option in Open3D.

### References

An informative blog post describing EDL: https://www.esri.com/arcgis-blog/products/arcgis-pro/3d-gis/eye-dome-lighting/

### Additional information

Here is an examples of using EDL in Cloud Compare. The view point is the same in both images. The second has EDL turned on (and point size increased).