Draft: Use external Package for FHI-aims IO interface

[tpurcell90]

Summary

Major changes:

• moved FHI-aims specific content into a separate package (pyfhiaims) for ease of maintenance (stop multiple libraries from implementing the same basic interface)

Todos

If this is work in progress, what else needs to be done?

• Workout how to best test the aims io interface/dependency tracker
• check with community this does not break their setups

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]

If the idea is to move FHI aims to a new external package, I think it should be done completely. Then there is no need for the unit tests to be done here. It can be done in the new package. We can also remove all the FHI related test files.

[tpurcell90]

Okay that is reasonable, I will move the tests there.