switch country name tokens to new word table layout

lib-sql/tokenizer/icu_tokenizer_tables.sql

@@ -8,6 +8,9 @@ CREATE TABLE word_icu (
 
 CREATE INDEX idx_word_word_token ON word
     USING BTREE (word_token) {{db.tablespace.search_index}};
+-- Used when updating country names from the boundary relation.
+CREATE INDEX idx_word_country_names ON word
+    USING btree((info->>'cc')) WHERE type = 'C';
 GRANT SELECT ON word TO "{{config.DATABASE_WEBUSER}}";
 
 DROP SEQUENCE IF EXISTS seq_word;