[Logs] Soft deprecate legacy internal endpoints

[tonyghiani]

📓 Summary

There are logs internal API endpoints that won't be used anymore with the deprecation of Logs Stream. Although they don't directly impact the end user, it is worth to internally flag them as deprecated so that they won't be used anymore for internal features.

✔ Acceptance criteria

• The following HTTP APIs are all used for the Logs Stream application to work, which we are deprecating, hence we can soft deprecate these APIs as well with comments or the available deprecation APIs.
  • GET /api/infra/log_views/{logViewId}
  • PUT /api/infra/log_views/{logViewId}
  • POST /api/log_entries/highlights
  • POST /api/log_entries/summary
  • POST /api/log_entries/summary_highlights
• The log entries search strategy won't be used anymore and its registration can be soft-deprecated commenting on the registration step here.

[elasticmachine]

Pinging @elastic/obs-ux-logs-team (Team:obs-ux-logs)