Port LUE to GDAL 3.13

[kordejong]

At least:

/*! 8-bit unsigned integer (GDT_Byte in GDAL < 3.13) */ GDT_UInt8 = 1,
/** GDT_Byte is the name used before GDAL 3.13 for GDT_UInt8 */

[OliverSchmitz]

still defined in https://github.com/OSGeo/gdal/blob/master/gcore/gdal.h#L70 but I assume it will disappear eventually