Add support for FQDN Option from rfc 4704

[traceflight]

The FQDN option can be used to exchange information about a DHCPv6 client's Fully Qualified Domain Name (FQDN) and about responsibility for updating DNS resource records (RRs) related to the client's address assignments.
RFC4704

[leshow]

I think there is some work left to do here for dhcpv6, we can leave this open if you want? You could manually pull the data out of UnknownOption but we support a first class type for v4 client fqdn, we could do the same for v6.

[stappersg]

On Thu, May 18, 2023 at 05:32:05PM -0700, Evan Cameron wrote: ... we support a first class type for v4 client fqdn, we could do the same for v6.

Any existing examples of such in v6 _and_ v4, so this re-opened issue deserverse the label "good first issue"? Groeten Geert Stappers -- Silence is hard to parse

[leshow]

https://github.com/bluecatengineering/dhcproto/blob/master/src/v4/fqdn.rs has an example for v4, I'd imagine v6 would work similarly and could share types if the flags section is the same (I think it is).

This is the RFC:
https://www.rfc-editor.org/rfc/rfc4704.html#section-4

should be pretty straightforward if anyone wants to take it.