26834 merge crash

#26834: [tk-3dsmaxplus] 3ds Max is crashing if we merge 2 objects with the same name
Would it make sense to try to avoid this special stuff in the hook? How about adding a method to the 3dsmax engine which would be specific to 3dsmax and would help assist apps generally with this case (the loader cannot be the only case surely). With this approach, you are potentially adding the same logic in many different places - how about `app.engine.refocus_current_dialog()` or something? Then we could potentially change the meaning and behaviour of that later on in updates. When code is in a hook, is potentially not possible to change it once we have given it to clients, since they may customize it.