For consistency between all system tests, add missing setup.sh scripts
for tests which do not have one yet and ensure every setup.sh script
calls its respective clean.sh script.
Temporary files created by a given system test should be removed by its
clean.sh script, not its setup.sh script. Remove redundant "rm"
invocations from setup.sh scripts. Move required "rm" invocations from
setup.sh scripts to their corresponding clean.sh scripts.
3746. [func] New "max-zone-ttl" option enforces maximum
TTLs for zones. If loading a zone containing a
higher TTL, the load fails. DDNS updates with
higher TTLs are accepted but the TTL is truncated.
(Note: Currently supported for master zones only;
inline-signing slaves will be added.) [RT #38405]