CtfVisualizer: Never crash with uncaught exception when loading JSON

If we retrieve a value of a type that doesn't match the actual type in
the JSON, the JSON library throws an exception.
We should have checks to avoid this, but as a global measure never let
exceptions through to Qt Creator.

Change-Id: Ibfe830d745a94810f874ccca82b83d57ea72f31e
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/ctfvisualizer/ctfvisualizertool.cpp

@@ -162,8 +162,11 @@ void CtfVisualizerTool::loadJson()
     auto *task = new QFuture<void>(futureInterface);
 
     QThread *thread = QThread::create([this, filename, futureInterface]() {
-        m_traceManager->load(filename);
-
+        try {
+            m_traceManager->load(filename);
+        } catch (...) {
+            // nlohmann::json can throw exceptions when requesting type that is wrong
+        }
         m_modelAggregator->moveToThread(QApplication::instance()->thread());
         m_modelAggregator->setParent(this);
         futureInterface->reportFinished();