Merge branch 'refactor_model3' into 'develop'

GUI/coregui/Models/BeamItems.cpp

GUI/coregui/Models/BeamItems.h

GUI/coregui/Models/InstrumentItems.cpp

GUI/coregui/Models/InstrumentModel.cpp

GUI/coregui/Models/ItemCatalog.cpp

GUI/coregui/Models/TransformFromDomain.cpp

GUI/coregui/Models/TransformToDomain.cpp

GUI/coregui/Models/TransformToDomain.h

...ui/Views/InstrumentWidgets/DepthProbeInstrumentEditor.cpp

GUI/coregui/Views/InstrumentWidgets/GISASBeamEditor.cpp

...coregui/Views/InstrumentWidgets/OffSpecularBeamEditor.cpp

...ui/Views/InstrumentWidgets/PolarizationAnalysisEditor.cpp

GUI/coregui/Views/InstrumentWidgets/SpecularBeamEditor.cpp

Tests/UnitTests/GUI/TestSavingSpecularData.cpp