iOS A11Y: Do not add children of invisible parent

Prevent children from invisible parents from showing up in the a11y
hierarchy. This fixes a problem on iOS which e.g. always adds hyperlink
children of QML Text items, even if the Item itself is invisible.

Pick-to: 6.3 6.2
Change-Id: I88a6f08956b5fe78cb789a08f2078f96d7aa263c
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/plugins/platforms/ios/quiview_accessibility.mm

@@ -56,7 +56,7 @@
 
 - (void)createAccessibleContainer:(QAccessibleInterface *)iface
 {
-    if (!iface)
+    if (!iface || iface->state().invisible)
         return;
 
     [self createAccessibleElement: iface];