Removed the feedback slot from components

What does this MR do and why?

In this MR we:

• remove the feedback slot from all the components and make it an integral part of the message component in the chat
• the User Feedback component itself becomes configurable so that all consumers of this component could pass down the name of the tracking event
• the MR also moves the listing of the documentation sources on the documentation answers all the way down to the message component and move all the logic of the sources into a separate component.

Screenshots or screen recordings

How to set up and validate locally

• set up GitLab Duo chat
• Open GitLab chat
• Ask any documentation question ("How do I change my GitLab password?" for example)
• Check that:
  • the sources are listed below the answer
  • the sources have correct title and the icon
  • the link to leave feedback still opens the feedback modal

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.