[Case Modeler] Refactor duplicate classes: AdHocSubprocess, EmbeddedSubprocess, ReusableSubprocess

Classes AdHocSubprocess, EmbeddedSubprocess, ReusableSubprocess have two copies in bpmn and cm. Need to refactor duplicate classes.

The reason to have two copies is:
"This is a clone with different different labels, containment rule and title.
Unfortunately extending the foregoing and providing a new set of labels leads to errai-data-binding to barf presumably because there are two fields called "labels" (although I've also tried with a different name field and it leads to the same errors)."

e.g.
ReusableSubprocess