QmlProfiler: Move parts of model manager and trace file to Timeline

This way we can use the trace file loading and saving mechanism for
other profilers.

Change-Id: I98ec1cdde6f7abcea152cabf72e64d4e696dfa59
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/qmlprofiler/inputeventsmodel.cpp

@@ -165,6 +165,7 @@ void InputEventsModel::finalize()
 {
     setCollapsedRowCount(2);
     setExpandedRowCount(3);
+    QmlProfilerTimelineModel::finalize();
 }
 
 void InputEventsModel::clear()