contact-auditor: Report when there are multiple contacts

[jprenken]

Currently, when contact-auditor identifies a bad contact, it reports the registration ID, the bad contact, and the error.

It would be nice if it could also provide context, in some way, when the registration ID has more contacts than just the bad one. For example: ["mailto:[email protected]","tel:+1234567890"]

This context would be useful when relying on contact-auditor's output to manually remediate bad contacts.