Fix wrong tooltip behavior in `PopupMenu`s that have styles with top borders

scene/main/viewport.cpp

@@ -1400,6 +1400,11 @@ String Viewport::_gui_get_tooltip(Control *p_control, const Vector2 &p_pos, Cont
 		// Temporary solution for PopupMenus.
 		PopupMenu *menu = Object::cast_to<PopupMenu>(this);
 		if (menu) {
+			Ref<StyleBox> sb = menu->get_theme_stylebox(SceneStringName(panel));
+			if (sb.is_valid()) {
+				pos.y += sb->get_margin(SIDE_TOP);
+			}
+
 			tooltip = menu->get_tooltip(pos);
 		}