zones: remove knot_ from zone contents, rename zone-create.c

src/Makefile.am

src/knot/ctl/knotc_main.c

src/knot/dnssec/nsec-chain.c

src/knot/dnssec/nsec-chain.h

src/knot/dnssec/nsec3-chain.c

src/knot/dnssec/nsec3-chain.h

src/knot/dnssec/zone-events.c

src/knot/dnssec/zone-events.h

src/knot/dnssec/zone-nsec.c

src/knot/dnssec/zone-nsec.h

src/knot/dnssec/zone-sign.c

src/knot/dnssec/zone-sign.h

src/knot/nameserver/axfr.c

src/knot/nameserver/internet.c

src/knot/nameserver/nsec_proofs.c

src/knot/nameserver/update.c

src/knot/server/notify.c

src/knot/server/xfr-handler.c

src/knot/server/xfr-handler.h

src/knot/server/zones.c