rename class and files -> UnitConverter2D

Core/Fitting/SimDataPair.cpp

Core/Simulation/DepthProbeSimulation.cpp

Core/Simulation/GISASSimulation.cpp

Core/Simulation/OffSpecularSimulation.cpp

Device/Detector/UnitConverter2D.cpp

Device/Detector/UnitConverter2D.h

GUI/coregui/Models/DepthProbeInstrumentItem.cpp

GUI/coregui/Models/DomainObjectBuilder.cpp

Tests/UnitTests/Core/Core/DepthProbeConverterTest.cpp

Tests/UnitTests/Core/Instrument/OffSpecularConverterTest.cpp

Tests/UnitTests/Core/Instrument/RectangularConverterTest.cpp

Tests/UnitTests/Core/Instrument/SphericalConverterTest.cpp

auto/Wrap/doxygenDevice.i