Add PostgreSQL version of SQLite integ tests

- Add PostgreSQL throwaway database
- Add optional length parameter for random string
- Fix syntax for PostgreSQL in several areas
- Add optional ID for whereById type determination

src/RemoveFields.php

@@ -18,7 +18,7 @@ class RemoveFields
     public static function byId(string $tableName, mixed $docId, array $fieldNames): void
     {
         $nameParams = Parameters::fieldNames(':name', $fieldNames);
-        Custom::nonQuery(Query\RemoveFields::byId($tableName, $nameParams),
+        Custom::nonQuery(Query\RemoveFields::byId($tableName, $nameParams, $docId),
             array_merge(Parameters::id($docId), $nameParams));
     }