Some ideas of improving about router tree

目前的http的路由前缀树是基于httprouter最早的版本修改而来的，gin 同样是在httprouter的基础上不断迭代， https://github.com/gin-gonic/gin/commits/master/tree.go 从而可以看到，我原本打算基于gin版本pr一版上来，但发现 [fasthttp router](https://github.com/fasthttp/router) 性能同样优异，同时这里有个关于router 的benchmark,https://github.com/smallnest/go-web-framework-benchmark, 不知目前kitex 框架的对应场景是否有必要更新，以及如果要更新的话，更加适合基于那个版本的更新.

Compare Kitex’s current HTTP routing prefix tree with Gin’s tree.go history and the fasthttp/router implementation. Run or inspect the linked Go web-framework benchmark to assess whether the alternatives fit Kitex’s corresponding use case. Done means a justified choice about whether an update is needed and which implementation should be the basis.

Written by the indexing model from the issue text.