Use custom API route instead of doing var = ...first() if not var: raise HTTPException, etc.

[jpmckinney]

https://fastapi.tiangolo.com/how-to/custom-request-and-route/#accessing-the-request-body-in-an-exception-handler

Can then call one() instead of first() and handle sqlalchemy.orm.exc.NoResultFound globally.

Can do this in:

• get_user
• get_publication_as_user
• _get_publication_as_guest_via_uuid
• last_updated
• get_object_or_404
• get_credit_product
• confirm_credit_product
• login_mfa