Overlays devices hiden or not

[BenjaminDeleze]

Describe the Bug
Under the Overlays tab, the Camera devices, RangeFinder devices and Display devices sub menu are not always displayed.

It seems that, now, we need to select a robot and then go to the tab to see the actual sub menus.

Whereas before (in R2021b for example) the behavior was a bit more subtle:

• If there were several robots: you had to click on one to see the corresponding sub menus appeared.
• If there was only one: the robot was considered as selected and its sub menus appeared.

I think it is a regression but maybe it was done on purpose but if so, why?

Moreover, when going in the Overlays tab, it is not clear for me that the Devices are the one of the selected robot. As it is a general tab of Webots I would expect to see all the cameras and other devices of the world. However I think that it may be overwhelming, but we should at least change the name of the sub menus to make it clearer.

[omichel]

I believe this is a regression and we should fix it.

[stefaniapedrazzi]

This functionality was intentionally removed in #4350 (see description for the motivation).

I will check if it is feasible to show the overlays options for all the robots in the world.