Pyxtal

- Improve the site-symmetry notation 249
- Improve the handling of smiles string and representation for molecular crystals.

- update the get_transition function (247 248)
- Improve the get_1D_representation function
- update pymatgen dependency

Enabled the get_forcefield function

Improve the functionality for molecular module and manage PyPI upload via GitHub action.
To test...

- Drop the dependency of numba
- Reset py3Dmol to be optional 225
- add the initial support of close packing plane detection 196
- Fix some bugs in crystal structure generation with the pre-assigned wps

- [Fix Cannot extract the right mapping from spglib](https://github.com/qzhu2017/PyXtal/commit/56aa4152fda73ac232e456f29bfcd169e1d5484c) https://github.com/qzhu2017/PyXtal/issues/228

- [Fix PyXtal Build](https://github.com/qzhu2017/PyXtal/commit/d813fc455615d1e2ac28323879817cff6bfdfe60) https://github.com/qzhu2017/PyXtal/issues/226
- [update the pymatgen pandas dependencies to speed up pip install](https://github.com/qzhu2017/PyXtal/commit/9fdb4ec509da6a97a239a3ae4fcfa427dcf32eff)
- [fix the coordination error](https://github.com/qzhu2017/PyXtal/commit/90eb141e2ecca30e1d09d9f436a5775c128cdedc)
- [fix build bug and add wp.short_distances function](https://github.com/qzhu2017/PyXtal/commit/8811df1e4a6913f8b7b903aa5ca6c5ab3d7a31ce)
- [try to create optional deps](https://github.com/qzhu2017/PyXtal/commit/4983c375d00a872317290832834858eff74ec86c)
- [fix the issue for speical site in mol xtal](https://github.com/qzhu2017/PyXtal/commit/c5e7a1466667973de8d8a9246b57ee7180043b60)
- [fix the generation issue by adjusting lattice more frequently](https://github.com/qzhu2017/PyXtal/commit/bdb030f00ad4dbbae8550d3640beb534bbbd9bc8) https://github.com/qzhu2017/PyXtal/issues/224