move materials related fct to Sample, and avoid swig %rename

Examples/Python/sim21_Reflectometry/MaterialProfile.py

...ython/sim21_Reflectometry/MaterialProfileWithParticles.py

Sample/Processed/MultiLayerFuncs.cpp

Sample/Processed/MultiLayerFuncs.h

Wrap/swig/libBornAgainCore.i

Wrap/swig/libBornAgainSample.i

auto/Wrap/doxygenSample.i

auto/Wrap/libBornAgainCore.py

auto/Wrap/libBornAgainCore_wrap.cpp

auto/Wrap/libBornAgainSample.py

auto/Wrap/libBornAgainSample_wrap.cpp