Command line interface to select a monitoring station
the choice_c method is intendedto have the same behaviour as choice (which creates a widget in the graphical interface) but from the command line.
# S4 method for ref_env choice_c(object, stationMesure)
an object of class ref_env
a character vector of the monitoring station code (corresponds to stm_libelle in the tj_stationmesure_stm table)