Encapsulate cleaning function and restructure

geocoder/extension/expected/20_admin0_test.out

@@ -0,0 +1,27 @@
+-- Check that the synonym function is callable, should return NULL
+SELECT (admin0_synonym_lookup(Array['United States', 'ESP'])).*;
+       q       | adm0_a3 
+---------------+---------
+ United States | 
+ ESP           | 
+(2 rows)
+
+-- Check that the geocoding function is callable, should return success = false
+SELECT (geocode_admin0_polygons(Array['Spain', 'USA', ''])).*;
+   q   | geom | success 
+-------+------+---------
+       |      | f
+ Spain |      | f
+ USA   |      | f
+(3 rows)
+
+-- Add a few synonyms
+COPY admin0_synonyms (name, rank, created_at, updated_at, the_geom, the_geom_webmercator, cartodb_id, adm0_a3, name_) FROM stdin;
+-- Check that the synonym function is callable, should return their iso codes
+SELECT (admin0_synonym_lookup(Array['United States', 'ESP'])).*;
+       q       | adm0_a3 
+---------------+---------
+ ESP           | ESP
+ United States | USA
+(2 rows)
+