commands/focus: focus view inside container

seat_get_focus_inactive_floating and seat_get_focus_inactive_tiling do
not always return a view, so get the previously focused view from the
container with seat_get_focus_inactive_view. This is the i3 behavior.

sway/commands/focus.c

@@ -267,6 +267,11 @@ static struct cmd_results *focus_mode(struct sway_workspace *ws,
 		new_focus = seat_get_focus_inactive_tiling(seat, ws);
 	}
 	if (new_focus) {
+		struct sway_container *new_focus_view =
+			seat_get_focus_inactive_view(seat, &new_focus->node);
+		if (new_focus_view) {
+			new_focus = new_focus_view;
+		}
 		seat_set_focus_container(seat, new_focus);
 
 		// If we're on the floating layer and the floating container area