Adding new B+ -> 3h pi0 phase space model (JIRATICKET-1970)
Closes JIRATICKET-1970
This is the cherry-pick of commit from MR !568 (closed) (JIRATICKET-1970.EvtBnoCBpto3hpi0 to master) for Sim09.
Had to be done by hand and conflicts in EvtGenExtra resolved due to difference in code for registration of models in Sim09 and master.