[Just for discussion] Classes for material property
Just a proposal for discussion. In the implementation, material parameters are passed to PDEs by a container
template<typename T_PARAMETER_TYPE, typename T_MAT_MODEL, typename T_MATRIX> class TensorParameter : public ParameterBase<T_PARAMETER_TYPE>
which allows flexibility for different material model and computing variable dependent parameters via variadic members.
The groundwater problem is used for test.