Move Fermi-Hubbard publication data fetching

[Mounika-2604]

Resolves #125.

Summary

Following the decision in #125 to keep publication data fetching in the experiment modules:

• Added get_publication_data as an alias for fetch_publication_data in recirq/fermi_hubbard/publication.py.
• Re-exported both functions in recirq/fermi_hubbard/__init__.py.
• Added a unit test in publication_test.py to verify the alias and export.

Testing

• Ran pytest locally on recirq/fermi_hubbard/ (all tests passed).

[Mounika-2604]

Hi @mhucka, the changes for this issue are ready. Could you please review the PR when you have a chance? Thank you!

[mhucka]

The PR description is longer than the changes in the PR itself. It was obviously written by an AI agent. Don't just copy-paste the output from an agent. Summarize what is being done in your own words. Please respect the time of your human reviewers.

[Mounika-2604]

I apologize for that, @mhucka. You're completely right — the previous description was unnecessarily verbose for such a small change.

I have updated the PR description with a concise summary of what was actually changed. Thank you for pointing that out and for taking the time to review.