add explicit values to l1t::GlobalObject enum

[missirol]

PR description:

This PR implements one of the suggestions discussed in #42719 (adding explicit values to enum entries), in order to avoid introducing non-backward-compatible changes to the RAW data tier when modifying the enum l1t::GlobalObject (see #42634 (comment) and replies).

While editing GlobalObject.cc, I noticed a mismatch between this and this. I tried to re-implement the corresponding utilities to avoid such mistakes in the future (these utilities seem to be used in CMSSW only for LogDebug statements, so they are fairly unconsequential).

A related unit test is also added.

Merely technical. No changes expected.

PR validation:

The new unit test passes.

If this PR is a backport, please specify the original PR and why you need to backport that PR. If this PR will be backported, please specify to which release cycle the backport is meant for:

N/A

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-43022/37194

• This PR adds an extra 40KB to repository

[cmsbuild]

A new Pull Request was created by @missirol (Marino Missiroli) for master.

It involves the following packages:

• DataFormats/L1TGlobal (l1)
• L1Trigger/L1TGlobal (l1)

@aloeliger, @epalencia, @cmsbuild can you please review it and eventually sign? Thanks.
@rovere, @Martin-Grunewald this is something you requested to watch as well.
@antoniovilela, @sextonkennedy, @rappoccio you are the release manager for this.

cms-bot commands are listed here

[aloeliger]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-486ff6/35262/summary.html
COMMIT: 06d758d
CMSSW: CMSSW_13_3_X_2023-10-18-1100/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/43022/35262/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially removed 1 lines from the logs
• Reco comparison results: 10 differences found in the comparisons
• DQMHistoTests: Total files compared: 50
• DQMHistoTests: Total histograms compared: 3357400
• DQMHistoTests: Total failures: 6
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3357372
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 49 files compared)
• Checked 214 log files, 167 edm output root files, 50 DQM output files
• TriggerResults: no differences found

[aloeliger]

+l1

[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. @rappoccio, @sextonkennedy, @antoniovilela (and backports should be raised in the release meeting by the corresponding L2)

[rappoccio]

+1