Add selection tree of labels and part entities

### 📝 Description of the feature

For complex models with a lot of faces, edges and labels it is essential to get a better visual feedback directly in the graphics display. A tree widget of the geometry and mesh entities would be helpfull. If you select the item or multiple items in the tree, it would be great, if these are highlighted in the 3d view and if a python string is shown that can be used to get direct access to this entity within python. Especially, if you create labels in prime, you want to see the result of the selection interactively in the display.

### 💡 Steps for implementing the feature

_No response_

### 🔗 Useful links and references

_No response_