status checks: put DNSSEC tests in a better order w.r.t. other tests

* If the PRIMARY_HOSTNAME is in a zone with a DS record set at the registrar, show any DNSSEC failure (but only a failure) immediately since it is probably the cause of other DNS errors displayed later.
* For zones, if a DS record is set at the register, do the DNSSEC test first because even the NS test will fail if DNSSEC is improperly configure.
* But if a DS record is not set, the this is just a suggestion to configure DNSSEC so offer the suggestion last --- after mail and web checks.

see https://discourse.mailinabox.email/t/dns-nameserver-gandi-glue-records-issues/105/3