The local NewtonRaphson is moved from MaterialLib/SolidModels to NumLib in order for further reusing.
This class provides a basic NewtonRaphson routine to handle the nonlinear constitutive relationships existing in the local problem. After being moved to NumLib , it can be reused by other processes, e.g the two-phase multicomponent process which I am working on now.
(p.s. Some of the changes are caused by running clang-format)

conservativeResize() is not working as expected.

Used to derive shapefunctions of lower order for example
as needed for pressure given displacement shape functions
in HydroMechanics process.

This trades a copy of nodes pointers vs. O(#Elements * #Nodes/2) complexity.