feat(engines): add workflow engine versions to info endpoint

[Alputer]

Closes reanahub/reana-client#734

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.22%. Comparing base (908aca2) to head (999d716).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #711      +/-   ##
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+ Coverage   60.13%   60.22%   +0.08%     
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  Files          32       32              
  Lines        3562     3570       +8     
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+ Hits         2142     2150       +8     
  Misses       1420     1420              

Files with missing lines	Coverage Δ
reana_server/rest/info.py	79.03% <100.00%> (+3.10%)	⬆️

[tiborsimko]

It would be good to make a connection to the workflow engine, so that it's apparent that Adage and Packtivity are important only for Yadage workflow engine information.

For example, instead of current output:

$ rc info --json | jq | grep -A 3 packtivity_version
  "packtivity_version": {
    "title": "Packtivity version",
    "value": "0.16.2"
  },

We could have:

  "yadage_packtivity_version": {
    "title": "Yadage Packtivity version",
    "value": "0.16.2"
  },

Or, using the word "engine" everywhere, we could do:

{
  "supported_workflow_engines": {
    "title": "List of supported workflow engines",
    "value": ["cwl", "serial", "snakemake", "yadage"]
  },
  "cwl_engine_version": {
    "title": "CWL engine version",
    "value": "3.1.20210628163208"
  },
  "cwl_engine_tool": {
    "title": "CWL engine tool",
    "value": "cwltool"
  },
  "snakemake_engine_version": {
    "title": "Snakemake engine version",
    "value": "8.24.1"
  },
  "yadage_engine_adage_version": {
    "title": "Yadage engine adage version",
    "value": "0.11.0"
  },
  "yadage_engine_version": {
    "title": "Yadage engine version",
    "value": "0.20.1"
  },
  "yadage_engine_packtivity_version": {
    "title": "Yadage engine packtivity version",
    "value": "0.16.2"
  }
}

One advantage is that this is could be a more evolution-friendly setup in case we would like to print out the supported Snakemake plugins etc one day. (Example: snakemake_engine_storage_plugin_xrootd_version and friends)