So, unfortunately oomd uses "io.system." rather than "io.systemd." as
prefix for its sockets. This is a mistake, and doesn't match the
Varlink interface naming or anything else in oomd.
hence, let's fix that.
Given that this is an internal protocol between PID1 and oomd let's
simply change this without retaining compat.
We don't care about the ordering, so we may just as well drop the numerical
prefixes that we normally use for sorting. Also rename some other samples
to keep width of output down to reasonable width.
