Make ScattererConfiguration::_rcf structure public

  dcomplex ***_dc0_matrix;

  //! \brief Vector of sphere radii expressed in m, with size [N_SPHERES].

  double *_radii_of_spheres;

  //! \brief Matrix of fractional transition radii with size [N_SPHERES x LAYERS].

  double **_rcf;

  //! \brief Vector of sphere ID numbers, with size [N_SPHERES].

  int *_iog_vec;

  //! \brief Vector of layer numbers for every sphere, with size [N_SPHERES].

  const int& max_layers = _max_layers;

  //! \brief Read only view on flag to control whether to add an external layer.

  const bool& use_external_sphere = _use_external_sphere;

  //! \brief Matrix of fractional transition radii with size [CONFIGURATIONS x LAYERS].

  double **_rcf;

  /*! \brief Build a scatterer configuration structure.

   *