libknot: move debug.h into common

src/Makefile.am

src/common/debug.h

src/knot/dnssec/nsec-chain.c

src/knot/dnssec/zone-events.c

src/knot/dnssec/zone-keys.c

src/knot/dnssec/zone-nsec.c

src/knot/dnssec/zone-sign.c

src/knot/nameserver/axfr.c

src/knot/nameserver/internet.c

src/knot/nameserver/ixfr.c

src/knot/nameserver/name-server.c

src/knot/nameserver/nsec_proofs.c

src/knot/nameserver/process_query.c

src/knot/nameserver/update.c

src/knot/server/notify.c

src/knot/updates/changesets.c

src/knot/updates/ddns.c

src/knot/updates/xfr-in.c

src/knot/zone/node.c

src/knot/zone/zone-contents.c