mv getter implementations to headers

GUI/Model/Device/MultiInstrumentNotifier.cpp

GUI/Model/Device/MultiInstrumentNotifier.h

GUI/View/Access/DataAccessWidget.cpp

GUI/View/Access/DataAccessWidget.h

GUI/View/Canvas/ColorMapCanvas.cpp

GUI/View/Canvas/ColorMapCanvas.h

GUI/View/Canvas/MaskEditorActions.cpp

GUI/View/Canvas/MaskEditorActions.h

GUI/View/Canvas/MaskEditorCanvas.cpp

GUI/View/Canvas/MaskEditorCanvas.h

GUI/View/Canvas/SpecularPlotCanvas.cpp

GUI/View/Canvas/SpecularPlotCanvas.h

GUI/View/Dock/DockWidgetInfo.cpp

GUI/View/Dock/DockWidgetInfo.h

GUI/View/Instrument/DistributionSelector.cpp

GUI/View/Instrument/DistributionSelector.h

GUI/View/Main/MainWindow.cpp

GUI/View/Main/MainWindow.h

GUI/View/Realspace/RealspacePanel.cpp

GUI/View/Realspace/RealspacePanel.h