Move Core unit tests in C++ files

Tests/UnitTests/Core/Detector/DetectorMaskTest.cpp

Tests/UnitTests/Core/Detector/OffSpecularConverterTest.cpp

Tests/UnitTests/Core/Detector/PolygonTest.cpp

Tests/UnitTests/Core/Detector/PrecomputedTest.cpp

Tests/UnitTests/Core/Detector/RectangularConverterTest.cpp

Tests/UnitTests/Core/Detector/RectangularDetectorTest.cpp

Tests/UnitTests/Core/Detector/RegionOfInterestTest.cpp

Tests/UnitTests/Core/Detector/SimulationAreaTest.cpp

Tests/UnitTests/Core/Detector/SpecialFunctionsTest.cpp

Tests/UnitTests/Core/Detector/SpecularDetector1DTest.cpp

Tests/UnitTests/Core/Detector/SphericalConverterTest.cpp

Tests/UnitTests/Core/Detector/SphericalDetectorTest.cpp

Tests/UnitTests/Core/Detector/testlist.h

Tests/UnitTests/Core/ExportToPython/PythonFormattingTest.cpp

Tests/UnitTests/Core/ExportToPython/testlist.h

Tests/UnitTests/Core/Fitting/FitObjectiveTest.cpp

Tests/UnitTests/Core/Fitting/FitObserverTest.cpp

Tests/UnitTests/Core/Fitting/SimDataPairTest.cpp

Tests/UnitTests/Core/Fitting/testlist.h

Tests/UnitTests/Core/Fresnel/DepthProbeSimulationTest.cpp