update zone_tree_apply calls to use new interface

src/knot/zone/estimator.c

src/knot/zone/estimator.h

src/knot/zone/semantic-check.c

src/knot/zone/zone-dump.c

src/libknot/dnssec/zone-sign.c

src/libknot/nameserver/name-server.c

src/libknot/updates/xfr-in.c

src/libknot/zone/zone-contents.c

src/libknot/zone/zone-contents.h

src/libknot/zone/zone-diff.c

src/libknot/zone/zone-tree.c

src/libknot/zone/zonedb.c

tests/ztree.c