[Feature Request] unbound: support for Hyperlocal caching (RFC 7706)

[UnderEu]

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• I have read the contributing guide lines at https://github.com/opnsense/core/blob/master/CONTRIBUTING.md
• I am convinced that my issue is new after having checked both open and closed issues at https://github.com/opnsense/core/issues?q=is%3Aissue

Is your feature request related to a problem? Please describe.

This request is not directly tied to a problem but it has the potential to improve overall performance on a local network and, at some degree, provide a workaround for eventual link outages regarding local DNS queries.

Describe the solution you like

unbound is an excellent recursive DNS solution and it performs very nice on my own implementations, however I learned about Hyperlocal caching (RFC 7706) and found out that many ISPs in my country use this feature to speed-up even more the DNS queries from their customers, thus speeding up queries and rendering an even better browsing experience.
Been testing this on my homelab, it works but currently requires manual configuration via CLI to properly enable it. It'd be nice to expose this configuration on the GUI, so integrators/maintainers would have the option to improve their setups' performance without requiring manual configuration via CLI.

Describe alternatives you considered

It currently requires manual configuration via CLI to properly enable it.
Another way is using a separate daemon to do the root caching and then setup unbound to reach this daemon for its queries - which, again, requires manual configuration via CLI.

Additional context

• RFC 7706 - Decreasing Access Time to Root Servers by Running One on Loopback
• APNIC - Expanding the DNS Root: Hyperlocal vs NSEC Caching
• Unbound for recursive DNS – plus Anycast and Hyperlocal
• Tutorial DNS Hyperlocal - Wiki BPF