Add remote IP address as EDNS subnet?

[mzealey]

It would be nice to have an option to allow passing through the remote IP address as an EDNS subnet option (/32). There should be an additional config parameter to say if there is an existing EDNS subnet option in the packet should it be replaced or passed through. That way we can easily get proper details about the source on the backend dns server in case we want to do custom rules by IP. Thanks!