When tabbing into a grid or list of items that are selectable, we want to focus the selected item when entering it. At the moment, we only focus the first or last item in the date chooser grid, rather than the selected item. Co-authored-by: Niklas Wimmer <niklas@viric.eu> Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/869>