RHadrons: migrate package to use TruthUtils helper functions

Follows: !75624 (merged)

• use TruthUtils functions rather than CustomPDGParser methods
• safe to call mesonino and sbaryon particles rhadron without changing logic

Notes on the differing naming conventions between CustomPDGParser and TruthUtils:

• The term R-Glueball refers to ~g g and ~g g g bound states in both packages
• The terms mesonino and smeson used in CustomPDGParser are deprecated terms for ~q qbar bound states. These are now described as R-Mesons which contain squarks.
• The term sbaryon used in CustomPDGParser is a deprecated term for ~q q q bound states. These are now described as R-Baryons which contain squarks.
• The term R-Baryon in CustomPDGParser refers to ~g q q q bound states, while in TruthUtils it refers to ~g q q q and ~q q q bound states.
• The term R-Meson in CustomPDGParser refers to ~g q qbar bound states, while in TruthUtils it refers to ~g q qbar and ~q qbar bound states.
• The term R-Hadron in CustomPDGParser refers to R-Baryons, R-Mesons and R-Glueballs, this is also true in TruthUtils, but the scope of the terms R-Baryon and R-meson have expanded as described above to include states containing squarks.