Update spglib dependency to be compatible with newer versions #110

Right now, the code uses spglib by directly passing a ASE structure.
However, newer versions of spglib (starting from 2.3) removed this functionalities. Therefore, we had to restrain spglib version to <=2.2 to have the code work.

This is, however, very easy to fix. We just need to create a wrapper. In the class cellconstructor.Structure.Structure we can add a new function get_spglib_cell() that transform the current structure in a spglib valid cell (see here).

Then, edit all the times spglib is called with get_ase_atoms(), replacing with the new function get_spglib_cell(). This should ensure that the code works correctly with the newest and future spglib versions.