Cleaned up copy functions.

src/dnslib/dname-table.c

src/dnslib/dname-table.h

src/dnslib/dname.c

src/dnslib/dname.h

src/dnslib/node.c

src/dnslib/node.h

src/dnslib/rdata.c

src/dnslib/rdata.h

src/dnslib/rrset.c

src/dnslib/rrset.h

src/dnslib/tests/realdata/dnslib/response_tests_realdata.c

src/dnslib/zone-contents.c

src/dnslib/zone-tree.c

src/dnslib/zone-tree.h

src/dnslib/zone.c

src/dnslib/zonedb.c

src/dnslib/zonedb.h

src/knot/server/name-server.c

src/knot/server/xfr-in.c

src/zcompile/zparser.y