Add moderated status to spamlogs index

What does this MR do and why?

add a moderated status to the spamlogs index, so Trust and Safety can more easily see if a user has been banned or blocked.

part of: gitlab-org/modelops/anti-abuse/team-tasks#364

Screenshots or screen recordings

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Enable akismet from http://localhost:3000/admin/application_settings/reporting
2. View spam logs: http://localhost:3000/admin/spam_logs
3. Ban or block users and watch the status change

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.