Add place=quarter to city subdivisions (#1065)

This adds `place=quarter` which was introduced in 2011 as a subdivision
of villages/towns/cities as a value that sits between `place=suburb` and
`place=neighbourhood`. It has by now been used over 40,000 times and is
rendered in the OSM-Carto.

layers/place/types.sql

@@ -2,7 +2,7 @@ DO
 $$
     BEGIN
         IF NOT EXISTS(SELECT 1 FROM pg_type WHERE typname = 'city_place') THEN
-            CREATE TYPE city_place AS enum ('city', 'town', 'village', 'hamlet', 'suburb', 'neighbourhood', 'isolated_dwelling');
+            CREATE TYPE city_place AS enum ('city', 'town', 'village', 'hamlet', 'suburb', 'quarter', 'neighbourhood', 'isolated_dwelling');
         END IF;
     END
 $$;