Add updatedAt to compliance v2 API responses (backport #1360)

[mergify]

Changelist

Add updatedAt to compliance v2 API responses. This is needed for CLOSE_ONLY to determine the date when the account will be put into BLOCKED state.

Test Plan

Unit tested.

Author/Reviewer Checklist

• If this PR has changes that result in a different app state given the same prior state and transaction list, manually add the state-breaking label.
• If the PR has breaking postgres changes to the indexer add the indexer-postgres-breaking label.
• If this PR isn't state-breaking but has changes that modify behavior in PrepareProposal or ProcessProposal, manually add the label proposal-breaking.
• If this PR is one of many that implement a specific feature, manually label them all feature:[feature-name].
• If you wish to for mergify-bot to automatically create a PR to backport your change to a release branch, manually add the label backport/[branch-name].
• Manually add any of the following labels: refactor, chore, bug.

Summary by CodeRabbit

• New Features
  • Introduced an updatedAt timestamp to the compliance reports, indicating the last update time.
• Documentation
  • Updated API documentation to include the new updatedAt field in compliance report responses.
• Tests
  • Enhanced test suites to validate the presence and correctness of the updatedAt field in compliance reports.

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This is an automatic backport of pull request #1360 done by [Mergify](https://mergify.com).