Heavily inspired by #15622. This adds:
systemctl service-log-level systemd-resolved
systemctl service-log-level systemd-resolved info
systemctl service-log-target systemd-resolved
systemctl service-log-target systemd-resolved console
We already have systemctl verbs log-level, log-target, and service-watchdogs.
Those two new verbs tie nicely into this scheme.
I'm not sure if the LogTarget property is sufficiently general to be made into
a property that can be generally implemented. It is very closely tied to the internal
systemd logic. The other two seem fine thoough.
Zbigniew Jędrzejewski-Szmek