DNS CAA Additional properties

The current implementation of CAA records in Cloudflare supports the three properties defined in RFC6844.

Several new properties have been introduced since then. The authority is the IANA Certification Authority Restriction Properties registry.

It would be useful if Cloudflare supported all of the available DNS CAA Properties, such as contactemail, contactphone, issuemail and issuevmc. It would also be useful if Cloudflare tracked changes to the registry, and added new properties as they are added.