QmlProfiler: Eliminate QStandardItemModel from statistics

This resolves the data duplication between model manager and statistics
models, that gets in the way of updating the details strings on the fly.

Task-number: QTCREATORBUG-20106
Change-Id: I1c4881f903402dff936267de03b84d05ab7c39ca
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/qmlprofiler/qmlprofilerstatisticsmodel.h

@@ -218,6 +218,9 @@ public:
     int columnCount(const QModelIndex &parent) const override;
     QVariant data(const QModelIndex &index, int role) const override;
     QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
+
+    bool setData(const QModelIndex &index, const QVariant &value, int role) override;
+
 signals:
     void dataAvailable();