Fix issue where response was an embedded json string

src/connector_postgres_v2/base_command.py

@@ -36,7 +36,7 @@ def _execute(self, sql: str, conn_str: str, handler: Any) -> ConnectorProxyRespo
                 conn.close()
 
         command_response: CommandResponseDict = {
-            "body": json.dumps(command_response_body),
+            "body": command_response_body,
             "mimetype": "application/json",
         }
         return_response: ConnectorProxyResponseDict = {
@@ -66,8 +66,8 @@ def handler(conn: Any, cursor: Any) -> None:
         return self._execute(sql, conn_str, handler)
 
     def fetchall(self, sql: str, conn_str: str, values: list) -> ConnectorProxyResponseDict:
-        def prep_results(results: dict) -> list:
-            return list(map(list, results))
+        def prep_results(results: list) -> list:
+            return list(map(lambda r: r[0][1:-1].replace('"', '').split(","), results))
         def handler(conn: Any, cursor: Any) -> list:
             cursor.execute(sql, values)
             return prep_results(cursor.fetchall())