new_node: removed obsolete RRSet getters

src/knot/ctl/knotc_main.c

src/knot/ctl/remote.c

src/knot/dnssec/zone-nsec.c

src/knot/dnssec/zone-sign.c

src/knot/nameserver/internet.c

src/knot/nameserver/ixfr.c

src/knot/nameserver/process_query.c

src/knot/server/notify.c

src/knot/server/zones.c

src/knot/updates/ddns.c

src/knot/updates/xfr-in.c

src/knot/zone/semantic-check.c

src/knot/zone/zone-diff.c

src/libknot/edns.c

src/libknot/packet/pkt.c

src/libknot/rrset-dump.c

src/libknot/rrset.c

src/libknot/rrset.h

src/libknot/tsig-op.c

src/libknot/tsig.c