Renamed `mutt2task` to `neomutt-2task`, and renamed `sync-mail` to
`neomutt-syncmail`.
Changed key maps accordingly. Also systemd service even though I don't
think I'll use it again.
If no hook should be run before syncing (or a user-defined hook) then
the warning should fall under that and not be run as part of it.
Additionally takes care of multiple decryption requirements in a row.