Herwig7 2 2 settings update

[Dominic-Stafford]

PR description:

Update the Herwig settings blocks so these work with the current version of Herwig. Also update the Powheg+Herwig test to use these blocks, and add tests/examples for Madgraph+Herwig with both mlm and FxFx merging. Will add documentation on how to use these on the Herwig interface twiki: https://twiki.cern.ch/twiki/bin/viewauth/CMS/Herwig7Interface

PR validation:

Checked that all three examples work (Powheg example is runTheMatrix workflow 535)

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-33227/21671

• This PR adds an extra 32KB to repository

[cmsbuild]

A new Pull Request was created by @Dominic-Stafford for master.

It involves the following packages:

Configuration/Generator
GeneratorInterface/Herwig7Interface

@SiewYan, @mkirsano, @cmsbuild, @GurpreetSinghChahal, @agrohsje, @alberto-sanchez can you please review it and eventually sign? Thanks.
@Martin-Grunewald, @alberto-sanchez, @mkirsano, @fabiocos this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[SiewYan]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9f2b31/13635/summary.html
COMMIT: 2da6891
CMSSW: CMSSW_11_3_X_2021-03-19-1100/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/33227/13635/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 37
• DQMHistoTests: Total histograms compared: 2639935
• DQMHistoTests: Total failures: 1
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2639912
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 36 files compared)
• Checked 155 log files, 37 edm output root files, 37 DQM output files
• TriggerResults: no differences found

[SiewYan]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[silviodonato]

+1