Add frontend support for profile banner

What does this MR do and why?

Adds the Vue component that renders the scan coverage recommendation banner on the group security configuration page, built on the backend foundation from !260445 (merged). Tracks three internal events for the banner, a view when it is shown, a click on its call to action, and a dismiss, each carrying the banner variant as a label.

References

Stacked on !260445 (merged)

Screenshots or screen recordings

Before	After
	\n \n \n \n .

How to set up and validate locally

1. In rails console, enable the feature flag for a group's root namespace

   group = Group.find_by_full_path('your-group')
   Feature.enable(:security_profile_banner, group.root_ancestor)

2. Visit http://127.0.0.1:3000/groups/your-group/-/security/configuration
3. The banner shows one of five states depending on the group's scan coverage, a warning when no scanner is configured, a tip recommending the other scanner once one passes 25% coverage, a tip to extend the same scanner below 25%, a tip to extend both scanners when neither passes 25%, and no banner once the rollout is complete
4. Click the call to action and confirm it opens the enable scanners wizard at its first step
5. Dismiss the banner and reload the page, it should stay hidden for 60 days
6. To disable the flag again

   Feature.disable(:security_profile_banner, group.root_ancestor)

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.