Refactoring: No remote input / output anymore

beat/backend/python/data.py

beat/backend/python/data_loaders.py

beat/backend/python/executor.py

beat/backend/python/helpers.py

beat/backend/python/inputs.py

beat/backend/python/message_handler.py

beat/backend/python/outputs.py

beat/backend/python/stats.py

beat/backend/python/test/mocks.py

beat/backend/python/test/test_algorithm.py

beat/backend/python/test/test_data.py

beat/backend/python/test/test_executor.py

beat/backend/python/test/test_in_memory_data.py

beat/backend/python/test/test_inputs.py

beat/backend/python/test/test_message_handler.py