Fix code for 3.8 and import cleanups

b_asic/__init__.py

b_asic/scheduler-gui/graphics_axes_item.py

b_asic/scheduler-gui/graphics_graph_item.py

b_asic/scheduler-gui/graphics_timeline_item.py

b_asic/scheduler-gui/icons/basic_rc.py

b_asic/scheduler-gui/icons/breeze_dark_rc.py

b_asic/scheduler-gui/icons/breeze_rc.py

b_asic/scheduler-gui/icons/misc_rc.py

b_asic/scheduler-gui/logger.py

b_asic/scheduler-gui/main_window.py