Camunda-modeler: Add BPMN diagram refactoring actions

[nikku]

This issue serves as an epic for BPMN refactoring actions in the Camunda modeler.

__Definition__

A refactoring action allows users to perform rather complex, repeatitive actions in a quick manner.

__Possible Actions__

• Wrap in sub-process
• Remove sub-process, keeping contents
• Remove participant, keeping contents (#529, https://github.com/bpmn-io/bpmn-js/issues/968)

__Overall Questions__

How to make actions accessible to the user?

Via multi-element context pad? Via edit menu / keyboard shortcut only (think about CTRL+1 to do anything in Eclipse)?

[falko]

Bulk actions:

• [ ] Bulk Property Change (#893)
• [ ] Bulk Morph (#892)

Sub-Process:

• [ ] Extract Subprocess / Call Activity and inverse operation
• [ ] Keep positions of Boundary Events and edge waypoints when resizing a Sub-Process (#655)
• [ ] Expanding a subprocess overlaps previous content (#1244)
• [ ] When expanding a Sub-Process, auto-apply the Space Tool to create space
• [ ] Add subprocess with start event included (#1242)

Events:

• [ ] Morph among Start/Intermediate/End Events without losing event config, e.g. morphing a message start event directly into a message intermediate event while keeping event type and all it's attributes
• [ ] Attach/detach intermediate/boundary events (#239, bpmn-io/bpmn-js#478)
• [ ] Detach boundary event when connecting host with event-based gateway (#1053)
• [ ] Auto Morph to Event Sub-Process by changing Start Event Type (#915)
• [ ] Auto Morph None Events when connecting Message Flows BPMN (#197, #914)
• [ ] Event Sub-Process Creation from Boundary Events

Labels:

• [ ] Entering 'Yes' or 'Ja' as a label on a sequence flow on a diverging XOR automatically adds 'No' resp. 'Nein' on the other sequence flow
• [ ] Automatically add a question mark to labels of exclusive and inclusive gateways

Space Tool:

• [ ] Participant/Pool local Space tool #178
• [ ] Flow element local space tool #876

Others:

• [ ] Swap elements (#837)
• [ ] Toggle/reverse Lanes
• [ ] Reordering of Lanes (bpmn-io/bpmn-js#969)
• [ ] Keyboard shortcuts for morphing Task/Event/Gateway types, e.g. Ctrl+U for User Task