Refactoring

[FNTwin]

Checklist:

• Was this PR discussed in a issue? It is recommended to first discuss a new feature into a GitHub issue before opening a PR.
• Add tests to cover the fixed bug(s) or the new introduced feature(s) (if appropriate).
• Update the API documentation is a new function is added or an existing one is deleted.

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Refactoring/Clean/Docstring branch.

• Refactored src/openqdc -> openqdc/
• Updated pyproject.toml
• Updated mkdocs.toml
• Tutorial notebook small update/rerun
• Package versioning
• Added a CLI to download datasets (raw or preprocessed) + some basic informations on what datasets we offer.
• DESS -> DES
• Added some missing dependency to env.yml file for docs generation.
• Upload and download progress bar.
• Fixed the import test
• Added a classmethod to instantiate the datasets without calling the init to allow the preprocessing of raw files or some debugging
• Upgraded environments and action files black version to >= 24 to fix the failing github actions
• TypeAlias changes to make it compatible with py3.8 and py3.9
• Some small cleaning around and some docstrings + new as_iter() method in the base class to return the dataset as iterator on the normal dictionary object or ase Atoms object.

[prtos]

Please update the documentation so the help can tell the user more info about the arguments.

[FNTwin]

Updated. Typer has also --help for the subcommands, I will make it more clear in the readme.