Move rendering of resize banner into the tick callback

Unifies all rendering in one place. And possibly fixes issues with
rendering in a resize callback on sway.

kitty/state.h

@@ -112,6 +112,7 @@ typedef struct {
     bool in_progress;
     bool from_os_notification;
     bool os_says_resize_complete;
+    unsigned int width, height;
 } LiveResizeInfo;