Introduction of serialization instances in support of ledger peer snapshot

[crocodile-dentist]

Description

This change adds support for serialization of ledger peers by defining instances for its subcomponent types. The snapshot type will be introduced in a future commit.

Checklist

• Branch
  • [x] Updated changelog files.
  • [ ] Commit sequence broadly makes sense
  • [x] Commits have useful messages
  • [ ] The documentation has been properly updated
  • [ ] New tests are added if needed and existing tests are updated
  • [ ] If serialization changes, user-facing consequences (e.g. replay from genesis) are confirmed to be intentional.
• Pull Request
  • [ ] Self-reviewed the diff
  • [ ] Useful pull request description at least containing the following information:
    • What does this PR change?
    • Why these changes were needed?
    • How does this affect downstream repositories and/or end-users?
    • Which ticket does this PR close (if any)? If it does, is it linked?
  • [ ] Reviewer requested