QmlProfiler: Replace QStringList with QString in event data

We never have multi-string event data and dragging around the list
everywhere just adds noise.

Change-Id: I4c73543464abea01d342e3f0a296ed1b05ee2a88
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/qmlprofilertimelinemodelproxy.cpp

@@ -117,7 +117,7 @@ void RangeTimelineModel::loadData()
         if (i == eventIdsByHash.cend()) {
             QmlRangeEventData rangeEventData = {
                 event.displayName,
-                event.data.join(QLatin1String(" ")),
+                event.data,
                 event.location,
                 lastEventId++ // event id
             };