DIMAP 2: handle the case where the Raster_Data element is in main file; fix to extract geodetic SRS; fix to extract geotransform from JPEG2000 file if not available in XML (adapted from patch by mats, #5018, #4826)

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@27221 f0d54148-0727-0410-94bb-9a71ac55c965