获取流量池列表

{
    "success": true,
    "flow_pool": [
        {
            "id": 0,
            "period": "string",
            "traffic_type": "string",
            "total_flow": 0,
            "used": 0,
            "usage_notice": 0,
            "threshold_trigger": 0
        }
    ],
    "total": 0
}