[Feature Request] Make UBI query_id optional

[jzonthemtn]

Is your feature request related to a problem? Please describe

In some cases, it may not be desirable for a client to generate a UBI on the client-side. In these cases, the query_id should be optional.

Describe the solution you'd like

If a query_id is not provided, UBI should generate a random query_id (likely a UUID) and return it in the ubi block of ext in the search response.

Additional context

This relates to UBI which is described in #12084 and #13545.

This issue can be assigned to myself.

[andrross]

[Triage - attendees 1 2 3 4]
@jzonthemtn Thanks for filing.

[jzonthemtn]

Closing this RFC because the initial implementation is now available at https://github.com/opensearch-project/user-behavior-insights and new issues can be created there.