call beam() and detector() w/o instrument()

Core/Export/SimulationToPython.cpp

Core/Simulation/DepthProbeSimulation.cpp

Core/Simulation/GISASSimulation.cpp

Core/Simulation/ISimulation.cpp

Core/Simulation/OffSpecularSimulation.cpp

Core/Simulation/SpecularSimulation.cpp

GUI/coregui/Models/TransformFromDomain.cpp

Tests/UnitTests/Core/Fresnel/DepthProbeSimulationTest.cpp

Tests/UnitTests/Core/Fresnel/SpecularSimulationTest.cpp

Tests/UnitTests/Core/Instrument/RectangularDetectorTest.cpp

auto/Wrap/libBornAgainBase_wrap.cpp

auto/Wrap/libBornAgainFit_wrap.cpp