create pg_trgm in database

add pg_trgm postgresql extension and contrib package for dependency

manifests/database/postgresql.pp

@@ -24,6 +24,9 @@
     }
     # get the pg contrib to use pg_trgm extension
     class { '::postgresql::server::contrib': }
+    postgresql::server::extension { 'pg_trgm':
+      database  => $database_name,
+    }
   }
 
   # create the puppetdb database