shorten name -> namespace SampleUtils::Multilayer

Core/Simulation/ISimulation.cpp

GUI/Models/GUIDomainSampleVisitor.cpp

Sample/Multilayer/MultiLayer.cpp

Sample/Multilayer/MultilayerUtils.cpp

Sample/Multilayer/MultilayerUtils.h

Sample/Processed/ProcessedSample.cpp

Tests/UnitTests/Core/Sample/MultiLayerTest.cpp