Add error alerts and badge for webhooks

What does this MR do and why?

Add alert and badge for webhooks that are disabled due to errors. The previous MR !76743 (merged) handled rate-limited webhooks.

• 4xx error (permanently disabled) as defined in issue #343990 (closed).
• 5xx error (temporarily disabled) as defined in issue #343991 (closed).

This MR also cleans up the code and adds all these error alerts to all views on the project / group / instance level.

Changelog: added

Screenshots or screen recordings

Page	4xx error (permanently disabled)	5xx error (temporarily disabled)
Webhooks index
Webhooks edit

How to set up and validate locally

• Visit Project > Settings > Webhooks (for example, http://127.0.0.1:3000/gitlab-org/gitlab-shell/-/hooks).
• Add at least 1 webhook (you can use any URL).
• Force some of the UI elements to render by adding || true to the conditions.
• Click Edit next to the webhook to view the alert (again by force rendering UI elements).

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 #343990 (closed)