Introduce the concept of broken catalog zones

The DNS catalog zones draft version 5 document describes various
situations when a catalog zones must be considered as "broken" and
not be processed.

Implement those checks in catz.c and add corresponding system tests.

bin/tests/system/catz/ns1/catalog-bad1.example.db

@@ -0,0 +1,13 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; SPDX-License-Identifier: MPL-2.0
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0.  If a copy of the MPL was not distributed with this
+; file, you can obtain one at https://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+@ 3600 SOA . . 1 86400 3600 86400 3600
+@ 3600 IN NS invalid.