[Task] Support split of large models

[BirgitBoss]

Is your task related to a problem? Please describe.
we just discussed it in the Joint BatteryPass Modelling Group taking the large BatteryPass aspect model of Catena-X into account.

I would be great to support split of such a large model into smaller aspect models.

Describe the solution you'd like
Select Entity or property, right mouse click "split", ask or propose new namespace
make a copy of the original model to not overwrite it, remove new model from original model
in case elements are shared with other parts of the model, suggest to make a shared aspect model