QmlDesigner: Add support for Key enums

Change-Id: I602c44283a4f8978d76117fd5b885ef34d377857
Reviewed-by: Qt CI Patch Build Bot <ci_patchbuild_bot@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/qmldesigner/designercore/model/texttomodelmerger.cpp

@@ -84,6 +84,9 @@ bool isGlobalQtEnums(QStringView value)
          u"TopToBottom",     u"UpArrowCursor",  u"Vertical",           u"WaitCursor",
          u"WhatsThisCursor", u"WheelFocus"});
 
+    if (value.toString().startsWith("Key_"))
+        return true;
+
     return std::binary_search(std::begin(list),
                               std::end(list),
                               QmlDesigner::ModelUtils::toStdStringView(value));