Merge modernize htc

[belforte]

this PR is not very clean, the list of commits is wrong. But I could nod find a way to make it work "by the book". Anyhow final code should be identical to current https://github.com/dmwm/CRABServer/releases/tag/modernize_HTC_0616 which works.

We can squash commits when merging.

I have not tested yet resubmissions with changed requirements (nCores, memory, b/w list).

[cmsdmwmbot]

Jenkins results:

• Python3 Pylint check: failed
  • 22 warnings and errors that must be fixed
  • 258 comments to review
• Pycodestyle check: succeeded
  • 304 comments to review

Details at https://cmssdt.cern.ch/dmwm-jenkins/view/All/job/DMWM-CRABServer-PR-test/2018/artifact/artifacts/PullRequestReport.html

[cmsdmwmbot]

Jenkins results:

• Python3 Pylint check: failed
  • 1 warnings and errors that must be fixed
  • 7 warnings
  • 259 comments to review
• Pycodestyle check: succeeded
  • 296 comments to review

Details at https://cmssdt.cern.ch/dmwm-jenkins/view/All/job/DMWM-CRABServer-PR-test/2019/artifact/artifacts/PullRequestReport.html

[cmsdmwmbot]

Jenkins results:

• Python3 Pylint check: succeeded
  • 7 warnings
  • 259 comments to review
• Pycodestyle check: succeeded
  • 296 comments to review

Details at https://cmssdt.cern.ch/dmwm-jenkins/view/All/job/DMWM-CRABServer-PR-test/2020/artifact/artifacts/PullRequestReport.html