Add stage2 L1 trigger matching + other features 81X

[battibass]

This PR extends the offline muon -> L1 muon matching functionalities with the following features:

1. Allows matching with stage 2 L1 muon candidates
2. Implements a "by quality" sorting logic in the matching code
3. Adds further output that simplifies the computation of results for trigger efficiency and SFs, given the issues described in [1,2]

the main user of the updated classes is Muon POG tag and probe.

[cmsbuild]

A new Pull Request was created by @battibass (Carlo Battilana) for CMSSW_8_1_X.

It involves the following packages:

MuonAnalysis/MuonAssociators

@cmsbuild, @monttj, @davidlange6 can you please review it and eventually sign? Thanks.
@bellan, @abbiendi, @jhgoh, @calderona, @HuguesBrun, @trocino 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

[davidlange6]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/15497/console

[cmsbuild]

+1
Tested at: 94c279c
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-16028/15497/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-16028/15497/summary.html