Move to VCPKG.

* Minor cleaning of CMakeLists.txt. Fix C++ warnings and Qt deprecation.
* Avoid using Python from virtual environment.

tests/runner/test_filemapper.cpp

@@ -5,9 +5,10 @@
 
 #include <QCoreApplication>
 
+#include <uibase/ipluginfilemapper.h>
+#include <uibase/iplugingame.h>
+
 #include "MockOrganizer.h"
-#include "ipluginfilemapper.h"
-#include "iplugingame.h"
 
 using namespace MOBase;