Undo-stack is lost when I drill into a decision

[marstamm]

Describe the Bug

When I use the drill-down option, I loose my command stack of the DRD

Steps to Reproduce

Steps to reproduce the behavior:

1. open a DRD
2. Add a decision + change it to decision table
3. Open the decision table
4. get back to DRD
5. Press CTR+Z
6. Nothing happens

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Expected Behavior

The command stack is persisted, I can undo once I am in the DRD viewer.

Alternative:
The command stack is global and I switch views when an action is performed in another element, similar to sub processes in bpmn-js

Environment

Please complete the following information:

• Browser: [e.g. IE 11, Chrome 69]
• OS: [e.g. Windows 7]
• Library version: [e.g. 2.0.0]

[philippfromme]

I can reproduce this. With the current implementation of separate command stacks for each editor I'd at least expect to be able to undo if I didn't make any changes except for switching the editor.