Persist dismissal of feedback alert in SAST Configuration

Resolves #340352 (closed)

What does this MR do and why?

This adds persistent dismissal of feedback alert in SAST Configuration Page. With the current implementation, alert shows up again after the page reload.

This MR cleans up few more things:

• Firstly, it uses a shared component DismissibleFeedbackAlert which takes care of storing dismissals in localStorage
• Refactors ConfigurationPageLayout components
  • Removes alert & dismissal related codebase, as it moved in the parent component
  • Keep it simple, just the template
• Also refactors DismissibleFeedbackAlert
  • Non-breaking changes as it is not being used by any component
  • Makes it more generic

Screenshots or screen recordings

No visual changes for alert

before	after (no change)

Dismissal in action

How to set up and validate locally

• Visit Project > Security & Comp. > Configuration > SAST
• It should be something like http://127.0.0.1:3000/flightjs/flight/-/security/configuration/sast
• Alert appears at the top of the page

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.