Support User DNS Record Management

[zicklag]

We need to get our DNS server more production ready before we really want to advocate people using Weird as their DNS server, but once we get it more solid and secure, we want to allow users to use Weird as a DNS server for their domain.

That means that they need to be able to set Weird as their nameserver in their registrar settings, and then they can edit their DNS records through their Weird profile instead of the registrar.

This is an optional way to setup a custom domain, if you want Weird to have 100% control over your domain, and you want to use it to configure any other DNS records.

This will also allow Weird to automatically create the correct TXT and CNAME/ALIAS records for hosting the user's pubpage under their domain.

This will even work if the registrar doesn't support features like CNAME flattening or ALIAS records which are needed for configuring Weird under an apex domain.