supervisor: update to allow autorun configuration

This adds possibility to completely configure updater (autorun) trough
supervisor. Advantage of this is that supervisor is the only place that
defines uci configuration for updater (at least if we are talking about
autorun) and because of that same API can be used on top of generally
different configuration. This is handy because of back compatibility
with Turris OS 3.x and introduced cleanup in Turris OS 4.x.
7 jobs for 4.0-config-support in 9 minutes and 1 second (queued for 3 seconds)
Status Name Job ID Coverage
  Test
passed cppcheck #223134

00:00:50

passed luacheck #223135

00:00:54

passed system-tests #223132

00:02:46

passed system-valgrind-tests #223133

00:05:11

passed unit-tests #223130

00:02:32

passed unit-valgrind-tests #223811

00:03:49

failed unit-valgrind-tests #223131

00:01:21