The backend knows exactly which op has executed, and it saves us having
to re-implement this logic on each client.
Fixes the browser table refreshing when toggling decks.
Instances can pass handled_by=self to more easily ignore events they
initiate.
Fixes ugly refresh when expanding/collapsing decks, but we're still
refreshing the card/notes area unnecessarily in that case.
Updating a deck via protobuf is now exposed on the backend, but not
currently on the frontend - I suspect we'll be better off writing
separate routines for the actions we need instead, and we get a better
undo description for free.
This is currently causing an ugly redraw in the browse screen, which
will need fixing.
