Entity BN - Update correction flow to work with alternate names

Update bn processor such that we are able to work with alternate_name entries where required. With the new data model, SPs will need to use alternate_name similar to the way we use a legal_entity record.

**TODOs**
Do following for bn processor(s) relevant to this ticket:
- [ ] Do work in legal name branch
- [ ] Update to work with alternate names and legal entities
- [ ] Update versioning logic where required. May be still using versioning approach used in old data model
- [ ] There may be some other misc updates required to get processor working. Update as appropriate.
- [ ] Update LegalEntity, AlternateName and Filings model manually in common models to match with legal api models as required
- [ ] Update worker.py as required
- [ ] Update tests relevant to this bn processor

Start with the bn processor's legal name branch and worker.py, then compare the common LegalEntity, AlternateName, and Filings models with the legal API models. Review the existing processor tests and versioning logic before making changes. Done means alternate_name and legal entity correction flows work, versioning is compatible with the new model, and relevant tests pass.

Written by the indexing model from the issue text.