ingest: Update ingestion library to be able to read hot archive bucket list

[tamirms]

PR Checklist

PR Structure

• This PR has reasonably narrow scope (if not, break it down into smaller PRs).
• This PR avoids mixing refactoring changes with feature changes (split into two PRs
  otherwise).
• This PR's title starts with name of package that is most changed in the PR, ex.
  services/friendbot, or all or doc if the changes are broad or impact many
  packages.

Thoroughness

• This PR adds tests for the most critical parts of the new functionality or fixes.
• I've updated any docs (developer docs, .md
  files, etc... affected by this change). Take a look in the docs folder for a given service,
  like this one.

Release planning

• I've reviewed the changes in this PR and if I consider them worthwhile for being mentioned on release notes then I have updated the relevant CHANGELOG.md within the component folder structure. For example, if I changed horizon, then I updated (services/horizon/CHANGELOG.md. I add a new line item describing the change and reference to this PR. If I don't update a CHANGELOG, I acknowledge this PR's change may not be mentioned in future release notes.
• I've decided if this PR requires a new major/minor version according to
  semver, or if it's mainly a patch change. The PR is targeted at the next
  release branch if it's not a patch change.

What

Add an iterator to the ingestion library which enumerates over evicted entries in the hot archive bucket list.
Also, add an example script which makes use of that iterator to find evicted and soon to be archived contract balances.

Why

CAP-0076 has demonstrated a case where it is useful to examine the hot archive bucket list. We should add this functionality to the ingestion library.

Known limitations

[N/A]

[Copilot]

Pull Request Overview

This PR adds support for reading evicted entries from the hot archive bucket list to the ingestion library. The changes enable CAP-0076 use cases that require examining hot archive bucket lists.

Key changes:

• Added NewHotArchiveReader function to create a reader for hot archive bucket lists
• Refactored bucket reading logic to support both live and hot archive bucket list types
• Added example script demonstrating usage for finding expiring SAC balances

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
ingest/checkpoint_change_reader.go	Core implementation for hot archive bucket list support
ingest/checkpoint_change_reader_test.go	Updated test calls to use new readBucketRecord method signature
ingest/tutorial/expiring-sac-balances/main.go	Example script showing how to find expiring SAC balances using both live and hot archive readers

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[Copilot]

Pull Request Overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

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[Copilot]

Pull Request Overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

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