Move openfermion functions to correct modules

[soranjh]

Context: The qchem functions that depend on openfermion and pyscf are all collected in the openfermion_pyscf module.

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[github-actions[bot]]

Hello. You may have forgotten to update the changelog! Please edit doc/releases/changelog-dev.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.67%. Comparing base (d90137d) to head (9921079).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #5863 +/- ## ========================================== - Coverage 99.68% 99.67% -0.01% ========================================== Files 421 421 Lines 40461 40165 -296 ========================================== - Hits 40332 40035 -297 - Misses 129 130 +1 ```

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[soranjh]

[sc-59835]