Merge branch 'ksk_zsk_active_plus' into 'master'

src/knot/dnssec/key_records.c

src/knot/dnssec/zone-keys.c

src/knot/dnssec/zone-keys.h

src/knot/dnssec/zone-sign.c

tests-extra/tests/dnssec/key_rollovers/test.py

tests-extra/tests/modules/onlinesign_rollovers/test.py