connecting/validateXXX

[ajaxpost]

功能描述

官方链接：https://x6.antv.antgroup.com/tutorial/basic/interacting#validatexxx

目前 validateXXX 只支持同步程序，我想从服务端获取某个节点的依赖关系，从而判断是否可以进行连线

目前是做不到这个功能的

期望解决方案

希望 validateXXX 函数们 可以支持返回一个 Promise 如果 reslove 代表即可连线 如果返回的 reject 代表不可以连线

[x6-bot]

👋 @ajaxpost

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To help make it easier for us to investigate your issue, please follow the contributing guidelines.
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[NewByVector]

好建议，欢迎提 PR。可以暂时通过下面方法解决：

1. 在 edge:connected 事件中发送请求到服务端
2. 如果验证失败，则将这条边删除