Resolve "Implement client-side secret detection for wikis"

What does this MR do and why?

Add client side secret detection for wiki page form

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

Create or edit a wiki page and add a token to trigger the secret detection warning

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #509601