Fix issues reported by cppcheck

src/HardwareSet/OpenXRSet/OpenXRHand.hpp

src/Modules/DataField/Program.cpp

src/Modules/GUI/GUI2D/WidgetContainer.cpp

src/Renderer/Program.cpp

src/Renderer/ProgramExtension.cpp

src/Renderer/ProgramExtension.hpp

src/SceneGraph/3DObjects/Material.hpp

src/SceneGraph/Misc/Model3D.cpp

src/SceneGraph/Misc/Model3D.hpp

src/SceneGraph/Misc/Model3DMeshNode.cpp

src/SceneGraph/Misc/Model3DMeshNode.hpp