Debugger: Move ownership of perspective dock widgets to plugins

Similar to the previous patch, but affecting more plugins: with dynamic
perspectives lifetime is better managed close to the code that knows how
to (re-)construct the items.

Change-Id: I0e7bfcf769d198ec2afa88b972be900baa1b6a46
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/qmlprofiler/qmlprofilerviewmanager.h

@@ -44,6 +44,7 @@ public:
     QmlProfilerViewManager(QObject *parent,
                            QmlProfilerModelManager *modelManager,
                            QmlProfilerStateManager *profilerState);
+    ~QmlProfilerViewManager();
 
     QmlProfilerTraceView *traceView() const { return m_traceView; }
     QmlProfilerStatisticsView *statisticsView() const { return m_statisticsView; }