Hide subitems of 0 item rows unless --verbose is used

0 of the linted certificates were revoked.
  0 of the 0 certificates has revocation certificates that are weaker than the certificate and should be recreated. (GOOD)
...
0 of the non-revoked linted certificates have at least one non-revoked, live, signing-capable subkey:
  0 certificates have at least one non-revoked, live, signing-capable subkey with a strong binding signature, but a backsig that uses SHA-1. (GOOD)

When a top level item has 0 items, please skip the child entries unless --verbose is used...

I agree that it's valuable to show that some checking has been done, but I think that the top level items are enough to show users the overview and if there aren't any items in a top level item, there really isn't much valuable in describing checks that aren't being done on 0 items because there aren't any items to check.