Making MENATE_R package available as an alternative model

Making MENATE_R package available as an alternative model, removing the need for a custom physics process
Request by NOvA; reported at the 27CM at Rennes

https://indico.cern.ch/event/1156193/contributions/5050619/attachments/2515508/4324676/IFCosmicRequirementsG420220926.pdf page 11

Some references:
Modeling interactions of intermediate-energy neutrons in a plastic scintillator array with Geant4 (Journal Article) | DOE PAGES, ref 28:
B. Roeder, ”Development and validation of neutron detection simulations for EURISOL”, EURISOL Design Study, Report: [10-25-2008-006-In-beamvalidations.pdf, pp 31-44] (2008).
https://www.eurisol.org/eurisol_ds//doc_details.php?operation=download&docu=804&type=25

Similarly with NucDeEx package https://github.com/SeishoAbe/NucDeEx

Also voiced by NOvA; Contact: Andrew Sutton

See p. 15 of Krzysztof's talk: https://indico.cern.ch/event/1455551/contributions/6139452/attachments/2941171/5167807/IFCosmicRequirementsG420241007.pdf