Improve queries per-geocoder using https://www.drupal.org/project/geocoder/issues/3406303
requested to merge issue/geo_entity-3419108:feature/geocode-query--geocoder-issue-3406303 into 1.0.x
Allow changing query to include geocoder specific parameters, for example restricting by country.
Meta data is passed into the query which can then be used by event listeners to add the geocoder specific parameters. Implements two examples of these, one restricting results by country for Nominatim, the other restricting by language for Photon.
Also converts country code to country name for string search.