Solve Preference dialogue for scheduler GUI

b_asic/GUI/arrow.py

b_asic/GUI/drag_button.py

b_asic/architecture.py

b_asic/gui_utils/color_button.py

b_asic/scheduler_gui/_preferences.py

b_asic/scheduler_gui/main_window.py

b_asic/scheduler_gui/main_window.ui

b_asic/scheduler_gui/operation_item.py

b_asic/scheduler_gui/scheduler_event.py

b_asic/scheduler_gui/scheduler_item.py

b_asic/scheduler_gui/signal_item.py

b_asic/scheduler_gui/ui_main_window.py

test/conftest.py

test/test_sfg.py