Gui: remove SoNavigationDragger (#12409)

Removed SoNavigationDragger files. These files are no longer used in the project

src/Gui/SoFCDB.cpp

@@ -67,7 +67,6 @@
 #include "SoFCVectorizeSVGAction.h"
 #include "SoFCVectorizeU3DAction.h"
 #include "SoMouseWheelEvent.h"
-#include "SoNavigationDragger.h"
 #include "SoTextLabel.h"
 #include "SoDatumLabel.h"
 #include "Inventor/MarkerBitmaps.h"
@@ -92,7 +91,6 @@ SbBool Gui::SoFCDB::isInitialized()
 void Gui::SoFCDB::init()
 {
     SoInteraction                   ::init();
-    RotTransDragger                 ::initClass();
     SoGLRenderActionElement         ::initClass();
     SoFCInteractiveElement          ::initClass();
     SoGLWidgetElement               ::initClass();