Add typing, renaming, convenience methods/properties

b_asic/GUI/__init__.py

b_asic/GUI/arrow.py

b_asic/GUI/drag_button.py

b_asic/GUI/main_window.py

b_asic/GUI/port_button.py

b_asic/GUI/properties_window.py

b_asic/GUI/select_sfg_window.py

b_asic/GUI/simulate_sfg_window.py

b_asic/GUI/simulation_worker.py

b_asic/operation.py

b_asic/schedule.py

b_asic/scheduler_gui/__init__.py

b_asic/scheduler_gui/main_window.py

b_asic/signal.py

b_asic/utils.py

test/test_gui.py

test/test_scheduler_gui.py