adding truth info to soft muon origin in AnalysisTop

This MR adds truth information on the origin of soft muons in AnalysisTop. The following options are added to the config files for AT:

• SoftMuonAdditionalTruthInfo True/False (default: False) -> decide if you want to store additional truth information on the particle-level origin for soft muons (see TopParticleLevel/TruthTools.h)
• SoftMuonAdditionalTruthInfoCheckPartonOrigin True/False (default: False) -> Decide if you want to store additional truth information on the parton-level origin for soft muons (see TopParticleLevel/TruthTools.h, this makes sense only if also SoftMuonAdditionalTruthInfo is True)
• SoftMuonAdditionalTruthInfoDoVerbose True/False (default: False) -> produce debug printouts for these options

since these options are by default disabled, the standard user won't experience any change to the AT behaviour. If these options are used, the following output is added to the output reco-level ntuples:

• softmu_parton_origin_flag -> flag with information on the partonic origin of the soft muon, see the corresponding enum in TopParticleLevel/TruthTools.h
• softmu_particle_origin_flag -> flag with information on the particle origin of the soft muon, see the corresponding enum in TopParticleLevel/TruthTools.h
• softmu_parent_pdgid -> pdg ID of the direct mother of the soft muon
• softmu_b_hadron_parent_pdgid -> pdg ID of the B hadron originating the muon for B->mu, B->C->mu, B->tau->mu, B->C->tau->mu decays
• softmu_c_hadron_parent_pdgid -> pdg ID of the C hadron originating the muon for C->mu, C->tau->mu, B->C->mu, B->C->tau->mu decays

Decorations such as SG::AuxElement::Accessor<const xAOD::TruthParticle*> Mother("truthMotherLink") and analougous truthBMotherLink truthCMotherLink (and more) are added to the soft muon, in case one user wants to retrieve links to these particles in a CustomSaver. A <const xAOD::TruthParticle*>("truthMuonLink") decoration is also added to the reconstructed-level soft muons, to easily retrieve the associated truth muon.

Changes to the code are relatively simple, apart from the ones in PhysicsAnalysis/TopPhys/xAOD/TopParticleLevel/Root/TruthTools.cxx which contains the core of code retrieving the information.

This code has been tested with Pythia8, Herwig7 and Sherpa samples. Due to loop in ancestors history in Sherpa, the parton information option cannot be used with Sherpa; there are protections based on the number of iterations when running through particle ancestors to protect from such loops, inspired to the analogous protections used in the MCTruthClassifier.