Add DAST site validation flow in the sidebar

Related issue: #387617 (closed)

Epic: &9611 (closed)

Follow-up task: #388397 (closed)

What does this MR do and why?

This shows a validate button in site profile summary for un-validation profiles.

• It reuses the existing DastSiteValidationModal
• It is controlled with a new feature flag

Screenshots or screen recordings

When feature flag is disabled (no change)	When feature flag is enabled (notice the validate button for profile with no validation)

Validation Modal

How to set up and validate locally

1. Enable the feature flag

   Feature.enable(:dast_site_validation_drawer)

2. Visit DAST security configuration page for any project: http://gdk.test:3000/flightjs/Flight/-/security/configuration/dast
3. Create or an existing site profile
4. Click the validate button.

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.