rm obsolete VectorItem

GUI/Model/Item/BeamItems.cpp

GUI/Model/Item/ParticleCoreShellItem.cpp

GUI/Model/Item/ParticleCoreShellItem.h

GUI/Model/Item/ParticleItem.h

GUI/Model/Item/RectangularDetectorItem.cpp

GUI/Model/Item/VectorItem.cpp

GUI/Model/Item/VectorItem.h

GUI/Model/MakeItem/ItemCatalog.cpp

GUI/Model/Types/VectorDescriptor.h

GUI/View/Instrument/PolarizationAnalysisEditor.cpp

GUI/View/Instrument/VectorEditor.cpp

GUI/View/Instrument/VectorEditor.h

GUI/View/MaterialEditor/MaterialEditorDialog.cpp

GUI/View/MaterialEditor/MaterialEditorModel.cpp

Tests/Unit/GUI/TestDetectorItems.cpp

Tests/Unit/GUI/TestSessionItemUtils.cpp

Tests/Unit/GUI/TestSessionModel.cpp

Tests/Unit/GUI/TestVectorItem.cpp