Merge branch 'main_cleanup' into 'master'

src/common/log.c

src/knot/conf/conf.c

src/knot/conf/conf.h

src/knot/ctl/knotc_main.c

src/knot/main.c

src/knot/server/server.c

src/knot/server/server.h

tests/conf.c

tests/server.c