Internal das client python module to call das_client wrapper

[smuzaffar]

backport of #15549

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for CMSSW_8_0_X.

It involves the following packages:

PhysicsTools/PatAlgos
Utilities/General

@smuzaffar, @Dr15Jones, @cvuosalo, @cmsbuild, @montjj, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@TaiSakuma, @imarches, @ahinzmann, @acaudron, @mmarionncern, @rappoccio, @wddgit, @Martin-Grunewald, @jdolen, @nhanvtran, @gpetruc, @schoef, @ferencek, @mverzett, @mariadalfonso, @pvmulder, @JyothsnaKomaragiri this is something you requested to watch as well.
@slava77, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[smuzaffar]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/14675/console

[cmsbuild]

+1
Tested at: d744861
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15567/14675/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15567/14675/summary.html