CompilationDbProjectManager: Sanitize project parsing

The parsing code used to access all kinds of stuff (e.g. the project
tree and the toolchain manager) from the non-UI thread, which is not
allowed.

Fixes: QTCREATORBUG-22420
Change-Id: I4be47919d7e543376d31826dd380f66f4e060458
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/compilationdatabaseprojectmanager/compilationdatabaseutils.cpp

@@ -38,6 +38,7 @@
 using namespace ProjectExplorer;
 
 namespace CompilationDatabaseProjectManager {
+namespace Internal {
 
 static QString updatedPathFlag(const QString &pathStr, const QString &workingDir)
 {
@@ -240,4 +241,5 @@ QStringList splitCommandLine(QString commandLine, QSet<QString> &flagsCache)
     return result;
 }
 
+} // namespace Internal
 } // namespace CompilationDatabaseProjectManager