Add tests for going from secure to insecure

Add tests for going from secure to insecure

Add two test zones that will be reconfigured to go insecure, by
setting the 'dnssec-policy' option to 'none'.

One zone was using inline-signing (implicitly through dnssec-policy),
the other is a dynamic zone.

Two tweaks to the kasp system test are required: we need to set
when to except the CDS/CDS Delete Records, and we need to know
when we are dealing with a dynamic zone (because the logs to look for
are slightly different, inline-signing prints "(signed)" after the
zone name, dynamic zones do not).