Support self-published IP geolocation feeds (RFC 8805)

[smokris]

Some ISPs provide RFC 8805 data feeds which are more up-to-date and accurate than the MaxMind GeoLite2 databases. I'd like to be able to use those feeds when possible.

I envision the plugin having a configuration option to provide a list of feed URLs (e.g. this one from T-Mobile), and an option for update frequency (e.g. hourly, daily, weekly).

Would this be a suitable addition to the geoip plugin, or should it be a separate plugin?