Adds new query for a snapshot of big ledger peers

[crocodile-dentist]

This change introduces a new query tag and handler to support retrieval of a snapshot of big ledger peers from the current tip of a node.

Changelog

- description: |
    Added `GetPeerSnapshot` block query
# uncomment types applicable to the change:
  type:
  - feature        # introduces a new feature
  - breaking       # the API has changed in a breaking way
  # - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  # - improvement    # QoL changes e.g. refactoring
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
  # - maintenance    # not directly related to the code
  # - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

A snapshot of big ledger peers is very useful when bootstrapping a node from scratch in the upcoming Genesis consensus mode. Since only some, or none, of these peers are available to a node from its own ledger when syncing up, a snapshot is a means of providing these relays to the diffusion layer to ensure that a node ends up on a good chain.

Checklist

• [x ] Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff

[carbolymer]

Good work, thanks. Few comments to make sure that this PR adheres to the conventions used here.

There are build failures too.

[carbolymer]

Actually, not blocking changes if this query is for eras >= Shelley.

[palas]

FYI: Because we now enforce the use of cabal-gild to format cabal files and, in order to reduce the amount of hassle, I have cherry-picked the appropriate commit into your PR. This will make the cabal-gild CI check pass for the PR. The commit should be discarded automatically as soon as you either rebase or merge the PR (since it is already in the main branch). Feel free to discard it if you want, but that will make the new required action to fail until you rebase.

[palas]

FYI: I have rebased your branch because we have done changes to the formatting. I have made a copy of the unrebased branch here: backup/mwojtowicz/query-ledger-peer-snapshot

[github-actions]

This PR is stale because it has been open 45 days with no activity.