Feature Request: allow passing the resolver ID as EDNS CPE ID

I'd like the ability to pass a device's Resolver ID in the CPE ID in the EDNS0 extension.

Dnsmasq already supports the ability to set the CPE ID to a static value to send to the upstream resolver. Enhancing Dnsmasq to set the CPE ID dynamically using Dnsmasq's existing 'tag' mechanism wouldn't be difficult.