Make copy and move notes action consistent with operating system

[laurent22]

Operating system

macOS

Joplin version

3.0.6

Desktop version info

No response

Current behaviour

Ref: https://discourse.joplinapp.org/t/cannot-easily-copy-notes/38472

• When dragging and dropping a note to a notebook, the displayed cursor icon should be a "move" icon (or no icon, but not a "+" icon). The action should be a move.
• When using the keyboard modifier (Opt), the action should become a copy. The cursor should change to a "+"

The logic should be similar for Windows and Linux but not sure what the keyboard modifier should be. Maybe "alt"?

Expected behaviour

No response

Logs

No response