mv axis exporters to Core/Export

Base/Axis/FixedBinAxis.cpp

Base/Axis/FixedBinAxis.h

Base/Axis/IAxis.h

Base/Axis/PointwiseAxis.cpp

Base/Axis/PointwiseAxis.h

Base/Axis/VariableBinAxis.cpp

Base/Axis/VariableBinAxis.h

Core/Export/PyFmt2.cpp

Core/Export/PyFmt2.h

Core/Export/SimulationToPython.cpp

Tests/UnitTests/Core/ExportToPython/PythonFormattingTest.cpp

auto/Wrap/doxygenBase.i

auto/Wrap/doxygenCore.i

auto/Wrap/libBornAgainBase.py

auto/Wrap/libBornAgainBase_wrap.cpp