restructure attribute list in s57classregistrar, fixes problems with attributes around 64K (#5226)

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@26392 f0d54148-0727-0410-94bb-9a71ac55c965
remove references to mks57 (#5225)

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@26393 f0d54148-0727-0410-94bb-9a71ac55c965