use new factory functions InBeam, UBeam

Device/Beam/Beam.cpp

Device/Beam/Beam.h

Examples/fit/scatter2d/consecutive_fitting.py

Examples/fit/scatter2d/expfit_galaxi.py

Examples/fit/scatter2d/fit2d.py

Examples/fit/scatter2d/minimizer_settings.py

Examples/fit/scatter2d/model1_cylinders.py

Examples/fit/scatter2d/model2_hexlattice.py

Examples/fit/scatter2d/multiple_datasets.py

Examples/scatter2d/ApproximationDA.py

Examples/scatter2d/ApproximationLMA.py

Examples/scatter2d/ApproximationSSCA.py

Examples/scatter2d/AxesInDifferentUnits.py

Examples/scatter2d/BeamDivergence.py

Examples/scatter2d/BiMaterialCylinders.py

Examples/scatter2d/BoxesWithSpecularPeak.py

Examples/scatter2d/BuriedParticles.py

Examples/scatter2d/ConstantBackground.py

Examples/scatter2d/CoreShellNanoparticles.py

Examples/scatter2d/CoreShellNanoparticles2.py