More precise filtering of elements in 3D viewer

[SaMuellerDLR]

Currently it is possible to filter root elements in the 3D viewer. However, for example when demonstrating the satellite to other people, it is also often useful to hide / not show certain sub elements which obscure the view (for example outer plates or tanks, etc).

It would be therefore useful to also be able to filter out sub elements in a tree. Probably changing the current filtering dialog.