Add pdf details to lear model

Determine what data is needed to identify the outputs and make them available to the ledger (filing date, colin event_ids, etc)

PR: https://github.com/bcgov/lear/pull/1972

The purpose of this is to create a shallow copy of the current filing record so that the work with migrating legacy outputs into LEAR can continue while Argus deletes data from the filing table

Need 3 tables, shadow_filing, shadow_business, legacy_outputs.
**shadow_filing** will be a cut down version of the filing's table with only the most essential basic information related to a filing
**shadow_business** will be a cut down version of the business/legal_entity table with only the data necessary to get endpoints that generate ledger entries. maybe just registration # and business name columns
**legacy_outputs** will hold the data necessary to track which outputs are attached to which colin_event_id, and which filing_id in LEAR. Has colin_event_id, filing_id, and doc_store_key
**doc_store_key** column is a guess at how doc store will work with legacy outputs not entirely sure on how that system operates and what endpoints it has nor how to actually retrieve outputs stored in it