Support to aims format from Structure instance

[ansobolev]

Summary

This pull request adds support for reading and writing files in FHI-aims geometry.in format to the Structure objects.

Major changes:

• Support for reading geometry.in file in Structure.from_file and Structure.from_str methods
• Support for writing FHI-aims formatted file in Structure.to method

Checklist

• Google format doc strings added. Check with ruff.
• Type annotations included. Check with mypy.
• Tests added for new features/fixes.
• If applicable, new classes/functions/modules have duecredit @due.dcite decorators to reference relevant papers by DOI (example)

Tip: Install pre-commit hooks to auto-check types and linting before every commit:

pip install -U pre-commit
pre-commit install

[shyuep]

Thanks!