RFE: Extend `upsdrv(svc)ctl` with a `status-all` to check all known NUT-related daemons or service units

One-stop solution to verifying if upsd, upsmon, NDE etc. are active and/or alive. Follows up from issue #2567 and some later PRs implementing it.

Note that not all of service units are daemons (e.g. path or timer ones), and not all daemons might run or even exist on a particular system (consult `MODE` of `nut.conf`? although further note that `upslog` etc. would not be impacted by it)