Cleanup the HepMCHelpers code

Cleanup the HepMCHelpers code:

• removed unused/replace rarely used functions
• code formatting
• switch to templated functions to avoid code duplication

This merge request affects 4 packages:

• Generators/GeneratorFilters
• Generators/TruthUtils
• Simulation/FastShower/FastCaloSim
• Simulation/ISF/ISF_HepMC/ISF_HepMC_Tools

Affected files list will not be printed in this case

Adding @zmarshal ,@jchapman as watchers

added 23.0 Generators JetEtmiss Simulation analysis-review-required review-pending-level-1 labels

WARNING: big files (>100K) are found in the changeset

100K in file Simulation/FastShower/FastCaloSim/src/FastShowerCellBuilderTool.cxx

CI Result SUCCESS (hash 0b57e7d8)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 72449]

lgtm

added review-approved label and removed review-pending-level-1 label

added analysis-review-approved label and removed analysis-review-required label

added review-approved-tier0 label

added review-approved-point1 label

mentioned in commit 51496d4a

merged

mentioned in merge request !63576 (merged)