Add eras to select tracking configuration for 2017 detector

[makortel]

This PR is an updated version of #13266. Original description:

Based on the discussion in the HN thread https://hypernews.cern.ch/HyperNews/CMS/get/edmFramework/3597/1/2/1/1/1/1/1/1/1/1/1/1/1/1/1/1.html
I did the simplest (of the proposed alternatives) modification to Eras.py fulfilling our (TRK) need to run three tracking configurations with the phase1 detector.

If this PR gets accepted, my plan for phase1 tracking era-migration is to do following two steps

1. Migrate the existing phase1 tracking (Phase1PU70) to trackingPhase1 era
2. Update trackingPhase1 era to the configuration in Update phase1 (2017) tracking sequence #13149, and move Phase1PU70-tracking to trackingPhase1PU70 era

Compared to #13266 the place of Run2_2017_tracking* is changed to address the comment by @davidlange6 in Feb 17 RECO meeting.

Tested in CMSSW_8_0_X_2016-02-17-1100, no changes expected.

@rovere @VinInn @davidlange6

[cmsbuild]

A new Pull Request was created by @makortel (Matti Kortelainen) for CMSSW_8_1_X.

It involves the following packages:

Configuration/StandardSequences

@cmsbuild, @franzoni, @davidlange6 can you please review it and eventually sign? Thanks.
@ghellwig, @GiacomoSguazzoni, @rovere, @VinInn, @Martin-Grunewald, @cerati, @dgulhan 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

[davidlange6]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/11384/console

[cmsbuild]

+1
Tested at: 5153f92
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13383/11384/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13383/11384/summary.html