Fixed more doxygen warnings.

src/common/errors.h

src/dnslib/debug.h

src/dnslib/dname.c

src/dnslib/error.h

src/dnslib/packet.h

src/dnslib/response.c

src/dnslib/tests/dnslib/edns_tests.h

src/dnslib/tests/dnslib/rdata_tests.h

src/dnslib/tests/dnslib/response_tests.h

src/dnslib/tests/dnslib/rrset_tests.h

src/dnslib/zone-dump.c

src/dnslib/zone.c

src/knot/other/debug.h

src/knot/other/error.h

src/knot/server/server.c

src/zcompile/zcompile-error.h

src/zcompile/zcompile.c