unify local variable names analyzer_dir, polarizer_dir

Core/Examples/StandardSimulations.cpp

Examples/fit55_SpecularIntro/PolarizedSpinAsymmetryFit.py

Examples/scatter2d/MagneticSpheres.py

Examples/varia/BasicPolarizedReflectometry.py

Examples/varia/PolarizedNoAnalyzer.py

Examples/varia/PolarizedNonperfectAnalyzerPolarizer.py

Examples/varia/PolarizedSpinAsymmetry.py

Examples/varia/PolarizedSpinFlip.py

Tests/Functional/PyCore/polmagcylinders2.py

Tests/Unit/Core/SpecularSimulationTest.cpp

Tests/Unit/Device/BeamTest.cpp