[1549] Migrations and models for recruitment performance reports

[elceebee]

Context

Some scaffolding for the the new recruitment performance reports (replacing the mid-cycle reports). This work is followed immediately by this PR https://github.com/DFE-Digital/apply-for-teacher-training/pull/9306

Changes proposed in this pull request

• Migration to create tables
• Basic models and associated specs.

Guidance to review

Link to Trello card

https://trello.com/c/wHhTrLWl

Things to check

• [x] If the code removes any existing feature flags, a data migration has also been added to delete the entry from the database
• [x] This code does not rely on migrations in the same Pull Request
• [x] If this code includes a migration adding or changing columns, it also backfills existing records for consistency
• [x] If this code adds a column to the DB, decide whether it needs to be in analytics yml file or analytics blocklist
• [x] API release notes have been updated if necessary
• [x] If it adds a significant user-facing change, is it documented in the CHANGELOG?
• [x] Required environment variables have been updated added to the Azure KeyVault