Removing objects should refresh tree view

Current Situation

When removing a js7 opject e.g. file order source the tree in the configuration view is not refreshed. The object is still visible.

Reproduce:

• create a workflow w1 with workflow variable file
• create a file order source f1 and assign w1 to f1
• remove f1

Desired Behavior

When removing an object the tree in the configuration view should be refreshed.