QmlDesigner: Collect events for telemetry plugin

For each action/event we want to track we
emit QmlDesignerPlugin::usageStatisticsNotifier() with an identifer.

This allows counting how many states, transitions, timelines were created
and we track every registered action.

More 'trace points' can be added later.

Change-Id: Ibb31e1b7e20d984a10697e05bb4417e7ad1b8980
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/components/transitioneditor/transitioneditorview.cpp

@@ -40,6 +40,7 @@
 #include <rewritertransaction.h>
 #include <variantproperty.h>
 #include <viewmanager.h>
+#include <qmldesignerconstants.h>
 #include <qmldesignericons.h>
 #include <qmldesignerplugin.h>
 #include <qmlitemnode.h>
@@ -203,6 +204,8 @@ ModelNode TransitionEditorView::addNewTransition()
         states = QmlVisualNode(root).states().allStates();
     }
 
+    QmlDesignerPlugin::emitUsageStatistics(Constants::EVENT_TRANSITION_ADDED);
+
     if (states.isEmpty()) {
         Core::AsynchronousMessageBox::warning(tr("No States Defined"),
                                               tr("There are no states defined in this component."));