Add deprecation notice to the Serverless UI

What does this MR do and why?

This MR make changes to the Serverless UI:

• adds the deprecation notice alert
• removes the survey banner
• updates the empty state text

Screenshots or screen recordings

How to set up and validate locally

To validate the change go to Infrastructure -> Serverless Platform

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 gitlab-org/configure/general#164 (closed)