Add x-kde-passwordManagerHint when copy from kwalletmanager
The change includes:
- copy from editor widget (override createMimeDataFromSelection)
- copy action in the context menu / hot key
Relevant support was added to klipper quite time ago in plasma 5, so can be test with klipper (when copying from kwalletmanager, it won't show up in klipper).
Edited by Xuetian Weng