the default value of dnssec-validation is 'auto', which causes
a server to send a key refresh query to the root zone when starting
up. this is undesirable behavior in system tests, so this commit
sets dnssec-validation to either 'yes' or 'no' in all tests where
it had not previously been set.
this change had the mostly-harmless side effect of changing the cached
trust level of unvalidated answer data from 'answer' to 'authanswer',
which caused a few test cases in which dumped cache data was examined in
the serve-stale system test to fail. those test cases have now been
updated to expect 'authanswer'.
Add a test case where updates are being made against a hidden primary
and two bump in the wire signers (the providers in the multisigner
model) serve the zone.
The test covers the same cases as for two primary providers that is:
- Add DNSKEY
- Remove (previously added) DNSKEY
- Add CDNSKEY
- Remove (previously added) CDNSKEY
- Add CDS
- Remove (previously added) CDS
