services/horizon: Update asset stats processor to ingest new restoration meta

[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

Fixes #5422 , #5599

This PR updates the asset stats processor to handle the new restoration meta which will be introduced in the upcoming stellar-core v23 release (see stellar/stellar-core#4623 ). The protocol 23 release will also implement eviction of archived ledger entries. The only ingestion processor in Horizon which ingests ledger entries which can be archived / evicted is the asset stats processor.

Now, we no longer store asset stats for archived contract balances. Instead, we immediately delete contract balances from the horizon db as soon as the ttl expires. This allows us to ignore the eviction meta as the ledger entry no longer exists in the horizon db by the time it is evicted.

This PR also adds a runtime check to assert that the stellar-core binary supports protocol 23. This check is necessary because we don't want to maintain support for both protocol 23 and protocol 21 / 22 versions of restoration meta (see #5599 for more details).

Known limitations

There is no integration test which exercises eviction because we still need a stellar rpc docker image which supports protocol 23 before we can run protocol 23 integration tests. Once that docker image is available, we create another PR that adds an eviction integration test.

However, the restoration meta is still exercised in the integration tests because I have updated the integration tests to use the experimental core build ( stellar/unsafe-stellar-core:22.1.1-2291.a50f3f919.focal-do-not-use-in-prd ) which implements the new restoration meta in all protocol versions.