[UI] Improve pasting a copied model element multiple times
Observed behavior:
- When a copied model element is pasted in a diagram for the first
time (e.g., a component in a component diagram), the following
measures are taken to help the user to distinguish the original from
the copy
- Element is copied with an offset (see #2344)
- The prefix “Copy of” is prepended to the name of the original
- However, when the same copied element is pasted another time, it is positioned at exactly the same position as the first copy (thanks to #2344, the name is included a suffix to distinguish the first and the second copy)
Expected behavior:
- The double offset is applied again to the second copy, i.e. the relative position of the second to the first copy is the same as the one of the first copy to the original
- This results in a stacked view of all pasted copies, growing to the bottom-right
(from redmine: issue id 2360, created on 2015-06-11, closed on 2016-05-18)