Ntv-pandas

- bug 12 (python 3.10)
- enh 4 (Unification of parameters in to_xarray, to_scipp and to_dataframe)
- add CI processus (Github Workflow)
- pre-commit integration

- extension to multidimensional interfaces
- Xarray interface (`to_xarray` method, `from_xarray` function)
- scipp interface (`to_scipp` method, `from_scipp` function)
- ENH 4 5 7 8 9

- bug install

- add `to_analysis` function to use `TAB-analysis`module
- add `check_relation` function to use `TAB-dataset.check_relation` method
- add pandas accessor for `to_analysis` and `check_relation`

- move `decode_ntv_tab` method in `ntv_util` module ('json_ntv')

- add User Guide
- add `equals` method (check names and cat.categories dtype)
- add pandas accessor for `to_json`, `equals` and `as_def_type`
- BUG 3: categorical with a single value