Reworked the POI mapping so that a subtype is available. Needed for wind_turbine, but might also prove useful later.

layers/poi/class.sql

@@ -62,7 +62,7 @@ SELECT CASE class
 $$ LANGUAGE SQL IMMUTABLE
                 PARALLEL SAFE;
 
-CREATE OR REPLACE FUNCTION poi_class(subclass text, mapping_key text)
+CREATE OR REPLACE FUNCTION poi_class(subclass text, mapping_key text, subtype text)
     RETURNS text AS
 $$
 SELECT CASE