Get order types supported by a specific connector.
This endpoint uses the MarketDataService to access non-trading connector instances, which means no authentication or account setup is required.
Args: request: FastAPI request object connector_name: Name of the connector (e.g., ‘binance’, ‘binance_perpetual’)
Returns: List of supported order types (LIMIT, MARKET, LIMIT_MAKER)
Raises: HTTPException: 404 if connector not found, 500 for other errors