Create a RunModel_CemaNeigeGR2M function
Coupling GR2M with CemaNeige has been requested a couple of times. Indeed, when much snow is present, it impacts monthly discharge significantly.
There is no reason why CemaNeige could not work at a monthly time step. However, the temperature gradient (gradT) applied in DataAltiExtrapolation_Valery (and maybe more things in this function) should take into account the case of a monthly time step.