This PR/ commit adds two new features to the w90 converter stored to the h5 archive:
1. Centres of Wannier functions: This can be obtained using the `read_wannier90_centres()` function. This would also be useful if one wants to shift Wannier centres back to the home unit cells on-the-fly in `dft_tool`.
2. High-symmetry k-path for band structure: This can be obtained using the `read_wannier90_symm_kpath()` function.
changes:
* read wannier centres and symmetry kpath from w90
* [fix] w90convert test after fix for kpt_basis stor
---------
Co-authored-by: Alexander Hampel <ahampel@flatironinstitute.org>