Get currently active ORDERS for the subaccount, optionally filtered by market and side. Includes OPEN resting orders and UNTRIGGERED conditional orders (TP/SL accepted on-chain but not yet triggered). Returns { orders: [...] }. This does NOT include filled positions — a filled market/limit order leaves NO open order, it becomes a POSITION (see get_positions). When there are 0 orders but open positions exist, the result carries a note pointing you there.