Validation is failing when users add an included node is into a DRD.

Actual: When users try to add a included node on a DRD, the "Decision Components" component shows duplicated elements, and the diagram validation fails with an infinite loading:

Expected: Users should not see duplicated elements, and the validation shouldn't fail.

To reproduce, import both models on this JIRA, and open the "reproducer.dmn" by following the steps in the GIF.