Emailer - update special resolution processor to work with alternate name changes

Update email processor(s) 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 email 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 worker.py as required
- [ ] Update tests relevant to this email processor

Start by locating the relevant email processor and worker.py, then read the legal name branch and its existing tests. Update the processor for alternate names and legal entities, review versioning and other required behavior, and update the relevant tests until the processor works with the new data model.

Written by the indexing model from the issue text.