add json tags to vs gateway pool display

[dhuckins]

🛠️ Description

adds json tags for json output
we encountered a bug expected gateway_pool and got GatewayPool

🔗 Additional Link

🏗️ Local Testing

👍 Checklist

• The PR has a descriptive title.
• Input validation updated
• Unit tests updated
• Documentation updated
• Major architecture changes have a corresponding RFC
• Tests added if applicable
• CHANGELOG entry added or label 'pr/no-changelog' added to PR

  Run CHANGELOG_PR=<PR number> make changelog/new-entry for guidance
  in authoring a changelog entry, and commit the resulting file, which should
  have a name matching your PR number. Entries should use imperative present
  tense (e.g. Add support for...)