Maser4py

- Update solo/rpw tnr and hfr reader in maser-data
- Update maser-plots to be compatible with new RpwTnrSurv.as_xarray()
- Update docs

- Add as_xarray() for ecallisto in maser-data
- Update data.py for wind, cassini and nda
- Update mixin classes
- Add spacepy as an extra in maser4py pyproject.toml

- Add as_xarray() for NDA/Routine (CDF) in maser-data
- Reduce processing time for in RpwHfrSurvSweeps class in maser-data
- Fix bug in RpwHfrSurv.as_xarray() in maser-data
- Make maser command line works with new architecture
- Update documentation

- Add maser-tools as a new maser4py submodule
- Replace "." by "-" in maser4py submodule package names
- Update README for each maser4py, maser-data, maser-plot and maser-tools
- Update documentation

- Add SOLO/RPW/HFR Data class in maser.data
- Update SOLO/RPW/TNR Data.sweep method in maser.data
- Update README
- Update pyproject.toml (tool.poetry.source gitlab_obspm not required anymore)