调用：https://api.mch.weixin.qq.com/pay/profitsharingaddreceiver接口，
服务商代子商户发起添加分账接收方请求
服务商商户号：1681885586
子商户商户号：1684838208

xml数据格式：

<?xml version=\"1.0\" encoding=\"UTF-8\"?><xml><mch_id>1681885586<\/mch_id><sub_mch_id>1684838208<\/sub_mch_id><appid>wx3803d6983f39a37f<\/appid><nonce_str>24fxb2har345w1snb7qa5zbywmxng4ri<\/nonce_str><sign_type>HMAC-SHA256<\/sign_type><receiver>{\"type\":\"MERCHANT_ID\",\"account\":1681885586,\"name\":\"\\u5e7f\\u4e1c\\u884c\\u7801\\u7f51\\u7edc\\u79d1\\u6280\\u6709\\u9650\\u516c\\u53f8\",\"relation_type\":\"SERVICE_PROVIDER\"}<\/receiver><sign>872E43FF5E0B89795455F839075FCF7F5545A0F471B1B56AF19A5DD00E2B7094<\/sign><\/xml>