* Add settings to Renderable to control whether the renderbin is updated based on Opacity
* Remove duplicate RenderBin specification for RenderableSphere
* Remove unnecessary RenderBin specifications of Lagrange points
* Don't automatically update the renderbin for RenderableLabel and RenderablePlane
* Remove extra `setRenderBinFromOpacity` from RenderableSpheres
* Move information about whether a renderable should be updated when disabled
* Some cleanup of Renderable class
* Don't update the renderbin automatically if the user specified the renderbin manually
* Add property in OpenSpaceEngine for fading duration when enabling / disabling
* Add interface for fadeable components and apply to renderable
* Make layers a fadeable component
* Make globelabels a fadeable component
* Make labelscomponent a fadeable, and give it an enabled property
* Make screenspace renderables fadeable components
* Introduce concept of parent fadeables, to fade out subowners with parent
* Make rings fadeable as well
---------
Co-authored-by: Alexander Bock <alexander.bock@liu.se>