Legal API: Enforce Required CertifiedBy Field Validation

According to the [filing schema](https://github.com/bcgov/business-schemas/blob/main/src/registry_schemas/schemas/filing.json#L42), the `certifiedBy` field is required. However, in the FE, for the following staff filings: Put Back On, Admin Dissolution, Registrar's Notation, and Registrar's Order, we pass an empty string for the certifiedBy field.

- Can we populate the certifiedBy field in the FE for these filings so we can enforce the required `certifiedBy` field across all filings or do we create a special exemption for these cases?

Start with the filing schema at the linked certifiedBy definition, then trace the FE submission paths for Put Back On, Admin Dissolution, Registrar's Notation, and Registrar's Order. Confirm whether each can provide a certifiedBy value; done means the required field is enforced for all four or a clearly documented exemption is implemented.

Written by the indexing model from the issue text.