listbox: Remove get_selected_row and row-selected from gtk4
Submitted by Debarshi Ray
The gtk_list_box_get_selected_row method and row-selected signal look like API bugs in gtk+ 3.x. They don't work with multiple selection, and don't have equivalent counterparts in the newer GtkFlowBox widget. In fact, GtkFlowBox directly went with multiple-selection friendly APIs which were later added to GtkListBox.
One could argue that those should be added to GtkFlowBox too for the sake of convenience when using single selection boxes.
However, the convenience argument doesn't sound too compelling to me. I think it's less confusing to have a one true way of getting the selected widgets and listening to selection changes.