Add accessor to HGCalDDDConstants

[lgray]

Add an accessor to provide information about the thickness of the silicon wafer.

An integer is returned with value 1,2,3, corresponding to 100um, 200um, 300um, respectively.

[cmsbuild]

A new Pull Request was created by @lgray (Lindsey Gray) for CMSSW_8_1_X.

It involves the following packages:

Geometry/HGCalCommonData

@civanch, @Dr15Jones, @ianna, @mdhildreth, @cmsbuild, @davidlange6 can you please review it and eventually sign? Thanks.
@ghellwig this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[lgray]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/11821/console

[cmsbuild]

+1
Tested at: d5e191b
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13677/11821/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13677/11821/summary.html

[ianna]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @Degano, @smuzaffar