list.py: Use HdyColumn for adaptive list view
HdyColumn allows for listviews to cleanly scale between desktop & mobile form factors while having appropriate widths at each size. For consistency with other apps using HdyColumn the max width is 700.
HdyColumn allows for listviews to cleanly scale between desktop & mobile form factors while having appropriate widths at each size. For consistency with other apps using HdyColumn the max width is 700.