ENTITY-FILER: Set last-ledger-timestamp

### Replace_With_Short_Descriptive_Name
## Description:
- last-ledger-timestamp is not getting updated when filings are applied
- [ ] update the filer to update the last-ledger-timestamp in pg lear

**Dependencies**
- [ ] entity-filer
- [ ] legal-api
- [ ] pg lear

**Acceptance Criteria**
- [ ] last-ledger-timestamp is updated to the date the 'effective date' of the filing (i.e. if it is an AR this date should be the date of the agm)

**Validation Rules**
- [ ] last-ledger-timestamp set to date of AGM if it is an AR (this includes combined AR)
- [ ] last-ledger-timestamp set to filing date if it is a standalone COA/COD

Ready to Build (DoR):
- [ ] Stakeholders have approved
- [ ] User story completed
- [ ] What are the dependencies
- [ ] Validation rules defined (UI, Data, Role-Action)
- [ ] Is a formal UAT required

Acceptance / DoD:
- [ ] Design / Solution accepted by Product Owner
- [ ] Acceptance criteria has been defined (happy path, known sad paths)
- [ ] Test coverage acceptable
- [ ] Peer Reviewed
- [ ] Accessibility reviewed and acceptable [checklist](https://github.com/bcgov/entity/docs/coding-standards/accessibility.md)
- [ ] UX Approved
- [ ] PR Accepted
- [ ] Production burn in completed