Verification of big ledger peer snapshot file

[crocodile-dentist]

Description

A check was added to verify if big ledger stake pools from the peer snapshot file match what is provided by the ledger once syncing reaches the point at which the snapshot was ostensibly taken at. If there's a mismatch, an error is raised.

Checklist

Quality

• [x] Commit sequence makes sense and have useful messages, see ref.
• [ ] New tests are added and existing tests are updated.
• [ ] Self-reviewed the PR.

Maintenance

• [ ] Linked an issue or added the PR to the current sprint of ouroboros-network project.
• [ ] Added labels.
• [ ] Updated changelog files.
• [ ] The documentation has been properly updated, see ref.