Cancel multiple orders

Cancels multiple orders in a single request. Specify exactly one of: mkt_ids (cancel all orders for the listed markets), oids (list of order UUIDs), nonces (list of uint64 nonces), or cl_oids (list of client order ID strings); mixing identifier types returns 400.

Returns three lists: orders that were successfully cancel-requested (cancel_req), orders that could not be canceled because they were not found, already filled, or already canceled (not_opened), and orders that already had a cancel request in flight before this call (already_cancel_req).

Requires authentication.