macOS: Don't send redundant geometry change events for top level windows

Top level windows already get their geometry changes via windowDidMove
and windowDidResize.

Change-Id: Ie6370aa290ef48c8b3ac770e77adb57ce43cbb47
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -1101,6 +1101,9 @@ void QCocoaWindow::setEmbeddedInForeignView()
 
 void QCocoaWindow::viewDidChangeFrame()
 {
+    if (isContentView())
+        return; // Handled below
+
     handleGeometryChange();
 }