cert-request: more specific errors in IP address validation
Update the IP address validation to raise different error messages
for:
- inability to reach IP address from a DNS name
- missing PTR records for IP address
- asymmetric PTR / forward records
If multiple scenarios apply, indicate the first error (from list
above).
The code should now be a bit easier to follow. We first build dicts
of forward and reverse DNS relationships, keyed by IP address. Then
we check that entries for each iPAddressName are present in both
dicts. Finally we check for PTR-A/AAAA symmetry.
Update the tests to check that raised ValidationErrors indicate the
expected error.
Part of: https://pagure.io/freeipa/issue/7451
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>