EgEfficiencyCorr_dumpNPs utility

This adds a new utility executable to the ElectronEfficiencyCorrection package, printing descriptions of the different SystematicVariations recommended by the tool. This can be used to select a subset of relevant nuisance parameters and avoid processing those that an analysis is not affected by (e.g. uncertainty sources at low pt).

The executable accomplishes this simply by scanning the eta/pt plane and checking which variations differ from nominal. This is not the most elegant way to do it, but it offers the advantage to probe the exact behaviour of the tool as used in analyses, rather than relying on specific helper methods which might get out of sync.

Command-line arguments allow to set different properties of the AsgElectronEfficiencyCorrectionTool relevant to the nuisance parameters scheme. For example:

[user@server]$ EgEfficiencyCorr_dumpNPs IdKey=Tight Year=2015 CorrelationModel=FULL                                          
xAOD::Init                INFO    Environment initialised for data access
dumpNPs                   INFO    Scanning the eta/pt plane, this will take a bit of time...
dumpNPs                   INFO    EL_EFF_ID_CorrUncertaintyNP0 --> 0 < |eta| < 2.47, pt > 4.5 GeV.
...
dumpNPs                   INFO    EL_EFF_ID_CorrUncertaintyNP15 --> 0 < |eta| < 2.47, pt > 4.5 GeV.
dumpNPs                   INFO    EL_EFF_ID_FULL_UncorrUncertaintyNP0 --> 0 < |eta| < 0.1, 4.5 < pt < 7 GeV.
...

A different usage mode summarizes the NPs needed for a given eta x pt range, per year:

[user@server]$ EgEfficiencyCorr_dumpNPs AnalysisEta=0.8..2,sym,nocrack AnalysisPt=30e3..35e3 IdKey=Tight
xAOD::Init                INFO    Environment initialised for data access
dumpNPs                   INFO    Scanning the eta/pt plane, this will take a bit of time...
dumpNPs                   INFO    
dumpNPs                   INFO    Relevant nuisance parameters for the year 2015:
dumpNPs                   INFO       ++ EL_EFF_ID_CorrUncertaintyNP0 to 15
dumpNPs                   INFO       ++ EL_EFF_ID_FULL_UncorrUncertaintyNP66 to 67
dumpNPs                   INFO       ++ EL_EFF_ID_FULL_UncorrUncertaintyNP69 to 70
dumpNPs                   INFO       ++ EL_EFF_ID_FULL_UncorrUncertaintyNP77 to 78
dumpNPs                   INFO       ++ EL_EFF_ID_FULL_UncorrUncertaintyNP80 to 81
dumpNPs                   INFO    
dumpNPs                   INFO    Relevant nuisance parameters for the year 2016:
...