So, this is fun. Apparently "DeckId" is considered preferable to the
"DeckID" were were using until now, and the latest clippy will start
warning about it. We could of course disable the warning, but probably
better to bite the bullet and switch to the naming that's generally
considered best.
Work in progress - still to do:
- renames appear as 'Update Deck' - easiest way to solve it would
be to have a separate backend method for renames
- drag&drop of decks not yet undoable
- since the undo status is updated after the backend method ends,
the older checkpoint() calls need to be replaced with an
update_undo_status() at the end of the call - if we just remove the
checkpoint, then the menu doesn't get updated
