Copy-paste does not take grid transformation into account

[m-ender]

Steps to reproduce:

1. New grid.
2. Open the "Transform" menu, rotate and/or flip the grid.
3. Place several elements like numbers in the grid.
4. Select everything (Ctrl+A).
5. Copy (Ctrl+C).
6. New grid.
7. Paste (Ctrl+V). --> the elements will get pasted as if we had not transformed the original grid.