Add ClickHouse to the performance bar

What does this MR do and why?

This MR adds ActiveSupport::Notification to ClickHouse queries and exposes stats on the performance bar.

Related to: #416719 (closed)

Screenshots or screen recordings

How to set up and validate locally

1. Set up ClickHouse and test data like it's described in !124295 (merged)
2. Add a random query to app/controllers/dashboard/todos_controller.rb index action:

Gitlab::ClickHouse::Client.select("select * from issues", :main)

3. Open your todo page and see the ch section on the performance bar.

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.