[PWGHF] Utils: Fix and improve type safety, const correctness, readability.

[vkucera]

• Fix multiplicity type (uint16_t):
  • PWGHF/Core/CentralityEstimation.h:getCentralityGenColl
  • PWGHF/D2H/TableProducer/dataCreatorCharmHadPiReduced.cxx
  • PWGHF/Utils/utilsEvSelHf.h:getOccupancyGenColl
• Fix collision rejection mask type (uint32_t):
  • PWGHF/D2H/TableProducer/dataCreatorCharmResoReduced.cxx
• Fix occupancy type (float):
  • PWGHF/Utils/utilsEvSelHf.h:getOccupancyGenColl
  • PWGHF/Tasks/taskMcValidation.cxx
• Fix wrong passing by reference:
  • PWGHF/Utils/utilsAnalysis.h:isCandidateInMassRange
  • PWGHF/Utils/utilsEvSelHf.h:fillHistograms
  • PWGHF/D2H/Tasks/taskFlowCharmHadrons.cxx:fillThn
  • PWGHF/D2H/TableProducer/dataCreatorJpsiHadReduced.cxx:fillMcRecoInfo
  • PWGHF/D2H/TableProducer/dataCreatorCharmResoReduced.cxx:fillMcRecoInfoDTrack
  • PWGHF/D2H/Tasks/taskFlowCharmHadrons.cxx:getQvecDtracks
• Fix missing member initialisation:
  • PWGHF/Utils/utilsEvSelHf.h:HfEventSelectionMc
• Add passing by reference:
  • PWGHF/Utils/utilsEvSelHf.h:setEventRejectionLabels
• Define HfDecayChannel type (int8_t).
• Define HfCollisionRejectionMask type (uint32_t).
• Remove unnecessary template:
  • PWGHF/Utils/utilsDerivedData.h:reserveTables...
• Use meaningful template typenames.
• Use const as much as possible.
• Use auto for assigning function return values.
• Use fully qualified names:
  • o2::hf_occupancy::getOccupancyColl
  • o2::hf_occupancy::getOccupancyGenColl
• Refer to enum definitions in fatal errors.
  • CentralityEstimator
  • OccupancyEstimator

[github-actions]

O2 linter results: ❌ 63 errors, ⚠️ 0 warnings, 🔕 53 disabled

[fgrosa]

Thanks!