Fix handling of categorical values to keep original ordinal numbers

src/gui_version/create_prediction_data_gui.py

src/gui_version/create_training_data_gui.py

src/gui_version/utilities/handle_categorical_values.py

src/plain_scripts/create_prediction_data.py

src/plain_scripts/create_training_data.py

src/plain_scripts/utilities/handle_categorical_values.py