FEATURE: Return geoname IDs from MaxMindDb (#16082)

The geoname IDs can be used by plugins to locate the user more precisely.

lib/discourse_ip_info.rb

@@ -101,6 +101,13 @@ class DiscourseIpInfo
           ret[:latitude] = result.location.latitude
           ret[:longitude] = result.location.longitude
           ret[:location] = ret.values_at(:city, :region, :country).reject(&:blank?).uniq.join(", ")
+
+          # used by plugins or API to locate users more accurate
+          ret[:geoname_ids] = [
+            result.continent.geoname_id, result.country.geoname_id, result.city.geoname_id,
+            *result.subdivisions.map(&:geoname_id)
+          ]
+          ret[:geoname_ids].compact!
         end
       rescue => e
         Discourse.warn_exception(e, message: "IP #{ip} could not be looked up in MaxMind GeoLite2-City database.")