Add process metadata file for work with eBPF agent

[mrproliu]

Now we have skywalking-rover, which could detect processes from the local machine. Also, go2sky is one of the official agents in the skywalking ecosystem. We could let these two projects cooperate. If the local machine already has service use go2sky, then the rover could find this process automatically. Finally, the rover side could collect, profiling, etc.

In principle, when go2sky performs keep alive with the backend, it would write a metadata file to the local (temporary directory) at the same time, which describes the information of the current process. The Rover side scans all processes, find out which processes contain this metadata file, and update the confirmed files. Finally, if go2sky sees that it has been confirmed, it would not modify the files again.

[codecov-commenter]

Codecov Report

Merging #156 (9d9c061) into master (2d02004) will decrease coverage by 6.19%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #156      +/-   ##
==========================================
- Coverage   71.02%   64.83%   -6.20%     
==========================================
  Files          21       22       +1     
  Lines         994     1089      +95     
==========================================
  Hits          706      706              
- Misses        236      329      +93     
- Partials       52       54       +2     

Impacted Files	Coverage Δ
reporter/grpc.go	51.15% <0.00%> (-0.72%)	:arrow_down:
reporter/grpc_env.go	45.45% <0.00%> (-14.55%)	:arrow_down:
reporter/grpc_opts.go	76.92% <ø> (-23.08%)	:arrow_down:
reporter/process.go	0.00% <0.00%> (ø)

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[wu-sheng]

I think 1.4.1 is released, this PR is in the wrong milestone.

@arugal Do we need plugin 1.4.1 release?

[arugal]

@arugal Do we need plugin 1.4.1 relea se?

Yes, I left out