Close bld/OSG floor: OSG 3.4.1 from source + port osgQt to Qt6 + wire BgViewer dtEntity

Migrate BuildingViewer (16 files: DDS members, m_logger inits, QOpenGLWidget); gui:3:bld.info + gui:3:bdv now load

qt6-after/qt6-migrated-legatus/Lts/Plugins/BuildingViewer/Common/BgViewer/viewerCtrl/viewwidget.cpp

@@ -3,7 +3,7 @@
 #include <QtWidgets/QApplication>
 #include <QtWidgets/QVBoxLayout>
 #include <QtCore/QEvent>
-#include <QGLWidget>
+#include <QtOpenGLWidgets/QOpenGLWidget>
 #include <QWindow>
 #include <dtEntity/log.h>
 
@@ -176,7 +176,7 @@ void ViewWidget::viewModeChanged()
 
 bool ViewWidget::isOpenGlWindowExposed() const
 {
-  QGLWidget *gl = qobject_cast<QGLWidget*>(m_pView);
+  QOpenGLWidget *gl = qobject_cast<QOpenGLWidget*>(m_pView);
   if (!gl || !gl->windowHandle())
     return false;
   return gl->windowHandle()->isExposed();