Function build_cancel_order_params 

pub fn build_cancel_order_params(
    cmd: &CancelOrder,
    token: String,
) -> KrakenWsCancelOrderParams

Builds WebSocket cancel_order parameters from a Nautilus cancel command.

Prefers venue_order_id (as order_id) over client_order_id (as cl_ord_id), mirroring the REST cancel path which prefers the venue identifier since Kraken always knows it.