Adding optional results filename extension
This MR adds the option to specify a parameter results_filename_extension
in the evaluation of the model.
This string is then appended to the results files, allowing to evaluate with e.g. another fc factor or testing something else without overwriting the default results.
If this parameter is not specified, the default filenames will be used (as it was until now).
E.g. specifying results_filename_extension: "_<fancy_extension>"
would result in the following filenames: