Provide Opentelemetry Trace Middleware

[weizhengde]

middleware can report trace when server receive request. Some web/rpc framework support middleware or configuration to report trace. For example, hertz、gorilla/mux、kitex

• https://github.com/hertz-contrib/obs-opentelemetry

• https://github.com/kitex-contrib/obs-opentelemetry

• https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/github.com/gorilla/mux/otelmux/mux.go

[kevwan]

We've integrated opentelemetry already for long time.