This function sets the First Order Region (FOR) processing method for a SeaSondeRCS object.
It validates the provided method using seasonder_validateFORMethod and assigns it to the
object's FOR_data attribute under FOR_method.
     
    
    Usage
    seasonder_setSeaSondeRCS_FOR_method(seasonder_cs_object, FOR_method)
 
    
    Arguments
- seasonder_cs_object
- A SeaSondeRCS object containing spectral and metadata information. 
- FOR_method
- A character string specifying the desired FOR processing method. Currently, only
- "SeaSonde"is supported.
 
 
    
    Value
    The updated SeaSondeRCS object with the specified FOR processing method set.
     
    
    Details
    The function first validates the provided method. If the method is valid, it is stored in the
FOR_data attribute of the SeaSondeRCS object under the FOR_method field. This setting
is later used in the processing workflow to guide FOR computation.