Analyze chat message attributes which does not require LLM

What does this MR do and why?

Analyze chat message attributes which does not require LLM.

Screenshots or screen recordings

https://www.youtube.com/watch?v=FnDZShsMEF4 (Gitlab Unfiltered)

How to set up and validate locally

1. Comment out https://gitlab.com/gitlab-org/gitlab/-/blob/6d0b85d8140d296116aa41b8c352639407ad0d41/ee/lib/gitlab/llm/completions/chat.rb#L74
2. ask chat a question
3. observe llm.log file to see that request to AI is sent
4. observe snowplow-micro for newly added attributes

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.

Related to #430975