overwrite in raster factors has a different meaning than overwrite in other capeml related functions

[srearl]

the overwrite parameter of write_raster_factors() relates to how the metadata of raster values should be constructed. Okay, but the overwrite parameter throughout the rest of the capeml* ecosystem signifies whether to overwrite an existing file. This should be the case for write_raster_factors() as well with a different parameter used to indicate overwriting the construction of raster content.