updated tests (not all finished yet)

src/data_handling/iterator.py

src/model_modules/model_class.py

src/run_modules/experiment_setup.py

src/run_modules/model_setup.py

test/test_data_handling/test_iterator.py

test/test_model_modules/test_model_class.py

test/test_modules/test_model_setup.py

test/test_modules/test_pre_processing.py