[NL] Integration: Rename Gauss to GaussLegendre.

NumLib/Fem/Integration/GaussLegendreIntegrationPolicy.h

NumLib/Fem/Integration/IntegrationGaussLegendrePrism.h

NumLib/Fem/Integration/IntegrationGaussLegendrePyramid.h

...ib/Fem/Integration/IntegrationGaussLegendreRegular-impl.h

NumLib/Fem/Integration/IntegrationGaussLegendreRegular.h

NumLib/Fem/Integration/IntegrationGaussLegendreTet.h

NumLib/Fem/Integration/IntegrationGaussLegendreTri.h

NumLib/Fem/Integration/IntegrationPoint.h

ProcessLib/HydroMechanics/LocalDataInitializer.h

.../LIE/HydroMechanics/LocalAssembler/LocalDataInitializer.h

...IE/SmallDeformation/LocalAssembler/LocalDataInitializer.h

ProcessLib/SmallDeformation/LocalDataInitializer.h

ProcessLib/Utils/LocalDataInitializer.h