Change hint format for main filtered search dropdown

What does this MR do?

Changes the hint format on the main filtered search dropdown from type<value> to type:value so it matches the required syntax to perform filtering

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Screenshots (if relevant)

Current	Proposed

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #29786 (closed)