Require that MCC3 ID's in PyGriffin son input file be defined in ascending order
@ahmedamin1 reported some PyGriffin failures that upon inspection resulted due to MCC3 cell ID's in the son input file not being defined in ascending order (i.e. MCC3 cell D should not be defined unless cells A B and C are also defined). A check can be added to precheck in PyGriffinConnect to ensure this condition is met by the user. Right now, all MCC3 cells in the input file can be retrieved with the following:
all_mcc3_id = self.user_object.list_mcc3_id
If cells aren't defined in this way, the convertor from ISOTXS to ISOXML ends up skipping ID's when assigning numeric ID's to each MCC3 cell