Add support for profiling kmesh controlplane

[hzxuzhonghu]

What would you like to be added:

Recently we have figured out some issues on perf, stability, i have a rough though, we can add some metrics to help profiling kmesh-daemon. Like

1. Basic CPU/Memory usage
2. xDS related metrics like xds response handling time., bpf map operations

Why is this needed:

Currently, kmesh-daemon is like a black box, we can see some xds configurations by dumping the bpf map. But we couldn't know whether it is consistent with xds response, which flow is slow, which object is memory costing, etc. This is super critical for production use.

[hzxuzhonghu]

we can use net/http/pprof package

[Okabe-Rintarou-0]

xDS related metrics like xds response handling time., bpf map operations

Shall we use Prometheus to expose custom metrics?

[hzxuzhonghu]

we can split some tasks, metrics can be one

[Okabe-Rintarou-0]

pprof will start a http server, shall we make the port configurable or use a default one?

[Okabe-Rintarou-0]

seems that pprof also supports custom profile

[Okabe-Rintarou-0]

/assign

[hzxuzhonghu]

done