Refactor: make vl_grid_to_2D and Gint_inout independent of LCAO_Matrix

[maki49]

demanded by #2460

[wenfei-li]

I have no objection to the changes and will not block it, but I also don't see how this improves on the readability and overall structure of the code. For example, the interface now reads:

        this->vl_grid_to_2D(pvpR_grid, *lm->ParaV, lgd, new_e_iteration, lm->Hloc.data(),
            std::bind(&LCAO_Matrix::set_HSgamma, lm, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4));

which seems a little bit cumbersome. I suggest we only accept these changes if it is absolutely necessary.

[maki49]

@wenfei-li I need to call grid integral in a new ESolver without using class LCAO_Matrix.
In this function (vl_grid_to_2D) a non-static function LCAO_Matrix::set_HSgamma is called, I need to remove this dependence. Considering of universality, I decided to pass in a custom setter here, in which both row- and col-major setting are supportable.

If LCAO_Matrix::set_HSgamma will be removed in future refactor, this cumbersomeness can be removed natually.