Avoid expanding QRC nodes in main thread

For CMake and Qbs projects and users of TreeScanner, where the tree is
already created in a separate thread.

Expanding the QRC nodes means reading and parsing the QRC files, which
can take up a considerable time (second(s)) if there are hundreds of
them in a larger project like Qt Creator.

Task-number: QTCREATORBUG-25783
Change-Id: I5ca818b9f75ea6e8ef23f837cc9e15df7e6630e1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/cmakeprojectmanager/fileapidataextractor.cpp

@@ -33,6 +33,8 @@
 #include <utils/qtcprocess.h>
 #include <utils/utilsicons.h>
 
+#include <projectexplorer/projecttree.h>
+
 #include <QDir>
 
 using namespace ProjectExplorer;
@@ -708,6 +710,7 @@ FileApiQtcData extractData(FileApiData &input,
     result.projectParts = generateRawProjectParts(data, sourceDirectory);
 
     auto pair = generateRootProjectNode(data, sourceDirectory, buildDirectory);
+    ProjectTree::applyTreeManager(pair.first.get()); // QRC nodes
     result.rootProjectNode = std::move(pair.first);
     result.knownHeaders = std::move(pair.second);