feat: Feature/secureli 494 refactor action.py

[doug-szeto-slalom]

secureli-494

Changes

• creates _update_config helper function to be used in verify_install
• creates _pre_install_checks helper function to be used in _install_secureli

Testing

• no additional tests, existing tests pass

Clean Code Checklist

• [x] Meets acceptance criteria for issue
• [x] New logic is covered with automated tests
• [x] Appropriate exception handling added
• [x] Thoughtful logging included
• [x] Documentation is updated
• [x] Follow-up work is documented in TODOs
• [x] TODOs have a ticket associated with them
• [x] No commented-out code included