Tracing: CtfVisualizer: Add percentage of total time to statistics

Adds a column for the percentage of the time of an event to the total
measurement time in percent.

Change-Id: Ic3298b4ef6f34cb893edd987e645c7cfb67458b5
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/plugins/ctfvisualizer/ctftracemanager.cpp

@@ -282,6 +282,7 @@ void CtfTraceManager::updateStatistics()
             }
         }
     }
+    m_statisticsModel->setMeasurementDuration(qint64((m_traceEnd - m_traceBegin) * 1000));
     m_statisticsModel->endLoading();
 }