[FEATURE] 消息接收器基类建议添加回复消息的方法

[bunnyi116]

在 MessageReceiverBase 中添加一个 virtual Task<string> SendMessage(MessageChain chain){ } 方法，在不同的接收器中重写它进行实现，这样可以订阅 MessageReceiverBase 统一进行回复

[ksharperd]

this will be solve at next major release, pls issue any question as u want.