[BUG] Write only auxiliary data used in L2 MTD
Currently, maja lists all the gipps found in the input directory. It is better to list only the auxiliary data used : for example, if the CAMS are in the input directory but the parameter Use_Cams is set to false, the Gipps associated to the CAMS will not be written in the MTD_ALL.xml (same issue with the Directional Correction and the gipp DIRCOR).