Function gmo_coin_rs2::private::order::request_order

pub async fn request_order(
    http_client: &impl HttpClient, 
    execution_type: &ExecutionType, 
    symbol: &Symbol, 
    side: &Side, 
    size: f64, 
    time_in_force: &TimeInForce, 
    price: Option<i64>, 
    losscut_price: Option<i64>
) -> Result<RestResponse<Order>, Error>

新規注文APIを呼び出す。