Updating Puppiproducer to include fillDescriptions

[alefisico]

PR description:

To test PUPPI at HLT for Run3/PhaseII, PuppiProducer has to be updated with the fillDescription function to be recognized in condfb. This PR introduces this function in that producer. This change should be completely transparent to the PUPPI algorithm itself, or any other part of CMSSW.

PR validation:

Run runTheMatrix.py -l limited -i all --ibeos, and all the test passed. Here is the output of it: https://cernbox.cern.ch/index.php/s/QbCjBhba83NjFCr

[cmsbuild]

A new Pull Request was created by @alefisico (Alejandro Gomez Espinosa) for CMSSW_10_6_X.

It involves the following packages:

CommonTools/PileupAlgos

@perrotta, @cmsbuild, @santocch, @slava77 can you please review it and eventually sign? Thanks.
@rappoccio, @ahinzmann, @riga, @jdolen, @gkasieczka, @clelange this is something you requested to watch as well.
@davidlange6, @slava77, @fabiocos you are the release manager for this.

cms-bot commands are listed here

[perrotta]

-1
(This will have to be modified anyhow once the review of #28020 is finished, all fixes suggested are integrated, and that master version of this PR will be ready to get merged. Let "-1" it for the moment.)

[cmsbuild]

Pull request #28016 was updated. @perrotta, @andrius-k, @kmaeshima, @schneiml, @tlampen, @christopheralanwest, @civanch, @mdhildreth, @peruzzim, @cmsbuild, @franzoni, @jfernan2, @fgolf, @fioriNTU, @slava77, @tocheng, @pohsun, @santocch, @fabiocos, @kpedro88, @davidlange6 can you please check and sign again.

[alefisico]

This is a backport version of this PR #28020

[perrotta]

-1
Please either rebase correctly, or prepare a brand new PR with the backport

[kpedro88]

-1
please follow http://cms-sw.github.io/tutorial-resolve-conflicts.html#backporting-a-pr to make a proper backport