Use replica DB servers for info_refs controller action

What does this MR do?

Use replica DB servers for info_refs controller action.

~1-3 million requests have db_primary_count >= 2 per day. ~6-8 million requests have db_primary_count >= 1 per day.

Related issues:

• #292895 (closed)
• #292894
• &5590 (closed)

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • [-] I have not included a changelog entry because _____.
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.