Add new TruthBinding::childTruthBinding method

Add new TruthBinding::childTruthBinding method to simplify creating TruthBindings for child particles.

This merge request affects 1 package:

• Simulation/ISF/ISF_Core/ISF_Event

This merge request affects 2 files:

• Simulation/ISF/ISF_Core/ISF_Event/ISF_Event/TruthBinding.h
• Simulation/ISF/ISF_Core/ISF_Event/ISF_Event/TruthBinding.icc

Adding @jchapman ,@lmijovic as watchers

added Simulation main review-pending-level-1 labels

CI Result SUCCESS (hash 656dd032)

	Athena	AthSimulation
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
For experts only: Jenkins output [CI-MERGE-REQUEST-EL9 9703] (remote access info)

Looks good, approving - L2

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

merged

mentioned in commit a5b22437