Camera modes other than scene camera assert when selecting non-active layer items

Way to reproduce (also easy to reproduce in other projects)

1. open project with several layers and objects inside said layers
2. In timeline view, select one layer
3. Go to "Front View"
4. In timeline, expand another layer and click on object inside that layer to make it active (= select an item from layer that was not selected when you entered Front view mode)
5. In 3D view, click in the approximate area of an object in the second layer (it is invisible due to a bug)
6. Code asserts in CUICRendererImpl::GetLayerPickSetup() (In Release mode, studio does not crash but you can actually drag invisible object around and see the result by going back to the Scene camera view)