Move admin0 server functions around

- move files to its right place
- add some boilerplate for test setup
- add tests

server/extension/sql/0.0.1/20_geocode_street.sql

@@ -0,0 +1,22 @@
+-- Geocodes a street address given a searchtext and a state and/or country
+CREATE OR REPLACE FUNCTION geocode_street(searchtext TEXT, city TEXT DEFAULT NULL, state_province TEXT DEFAULT NULL, country TEXT DEFAULT NULL)
+  RETURNS Geometry
+AS $$
+  import json
+  from heremaps import heremapsgeocoder
+
+  heremaps_conf = json.loads(plpy.execute("SELECT cdb_geocoder_server._get_conf('heremaps')", 1)[0]['get_conf'])
+
+  app_id = heremaps_conf['geocoder']['app_id']
+  app_code = heremaps_conf['geocoder']['app_code']
+
+  geocoder = heremapsgeocoder.Geocoder(app_id, app_code)
+
+  results = geocoder.geocode_address(searchtext=searchtext, city=city, state=state_province, country=country)
+  coordinates = geocoder.extract_lng_lat_from_result(results[0])
+
+  plan = plpy.prepare("SELECT ST_SetSRID(ST_MakePoint($1, $2), 4326); ", ["double precision", "double precision"])
+  point = plpy.execute(plan, [coordinates[0], coordinates[1]], 1)[0]
+
+  return point['st_setsrid']
+$$ LANGUAGE plpythonu;