Stunner - User interactions are not being well reverted

romartin@redhat.com tested to press ESC, while dragging a shape, which should just "cancel" the operation and return the shape to its initial state, and well the shape is displayed on the initial location as expected, but an error popup is being displayed from this point each time the user clicks on it, which results in the shape in some "wrong" state and it's not possible to use it regularly.

Also more feedback from kgaevski@redhat.com - Found some small issues there when cancelling drag by Esc button:

• If you moving just one not connected node and click Esc ->
  • Actual result: Quick menu hidden, but node still on current mouse position. If you move you move little bit more, node will be returned to initial position, the same for mouse button up event (node will be returned to initial position).
• If you dragging single node connected to another node(s) and press Esc button:
  • Actual Result: Quick menu hidden, sequence flows returns to it's initial position, but node itself still under actual mouse position. If you move mouse one more time or trigger mouse button up, node will be returned to it's initial position.
  • Expected result: both sequence flows and node itself will be returned to it's initial position
• If you dragging group of node and press Esc button:
  • Actual Result: all nodes and sequence flows will be moved back to initial position, but group Selection will be still in same state during dragging.
  • Expected Result all nodes and selection area will be restored to initial state.

This ticket has been generated from https://issues.jboss.org/browse/RHPAM-1773