refactor: Change type for city.id to bigint

Refs: #92

Author: ghusta

scripts/world.sql

@@ -10,7 +10,7 @@ BEGIN;
 SET client_encoding TO 'UTF8';
 
 CREATE TABLE city (
-    id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    id bigint GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
     name text NOT NULL,
     country_code character(3) NOT NULL,
     district text NOT NULL,
@@ -44,7 +44,7 @@ CREATE TABLE country (
     local_name text NOT NULL,
     government_form text NOT NULL,
     head_of_state text,
-    capital integer,
+    capital bigint,
     code2 character(2) NOT NULL
 );