[Global Menu] Respect toplevel menu action visibility

Kolourpaint has hidden "Tools" menu, which would show up in
global menu otherwise.

Moreover, don't `void*` cast so QML can access the `QAction`

BUG: 443505


(cherry picked from commit 2e056ed6e5)

applets/appmenu/package/contents/ui/main.qml

@@ -114,7 +114,7 @@ Item {
 
                 down: pressed || plasmoid.nativeInterface.currentIndex === index
 
-                visible: text !== ""
+                visible: text !== "" && model.activeActions.visible
                 onClicked: {
                     plasmoid.nativeInterface.trigger(this, index)
 

applets/appmenu/plugin/appmenumodel.cpp

@@ -242,7 +242,7 @@ QVariant AppMenuModel::data(const QModelIndex &index, int role) const
         if (role == MenuRole) {
             return QString();
         } else if (role == ActionRole) {
-            return QVariant::fromValue((void *)(m_menu->menuAction()));
+            return QVariant::fromValue(m_menu->menuAction());
         }
     }
 
@@ -262,7 +262,7 @@ QVariant AppMenuModel::data(const QModelIndex &index, int role) const
     if (role == MenuRole) { // TODO this should be Qt::DisplayRole
         return actions.at(row)->text();
     } else if (role == ActionRole) {
-        return QVariant::fromValue((void *)actions.at(row));
+        return QVariant::fromValue(actions.at(row));
     }
 
     return QVariant();