PProf compatible endpoints

[vchuravy]

I am trying to use parca to scrape profiles from a long-running Julia process, and it support the pprof/go debug API

My config is:

scrape_configs:
  - job_name: "parca"
    scrape_interval: "10s"
    scrape_timeout: "60s"
    static_configs:
      - targets: [ '127.0.0.1:16825' ]
    profiling_config:
      pprof_config:
        julia:
          enabled: true
          path: '/profile'
          delta: true

and the last entry in the screenshot corresponds to the pprof_config. The delta: true adds the seconds option to the call.

So if we rename / or allow seconds in place of duration, then with some fixes to our pprof format
JuliaPerf/PProf.jl#106

We should be able to support pprof/go compatible tools.