Add informative banner to cluster security tab

What does this MR do and why?

Add informative banner to cluster security tab

• alert users to the fact that this tab only represents a sub-set of the vulnerabilities for the given project and direct them to the main vulnerabilities page
• hide alert based on cookie
• abstract constants out to a constants file
• add modal to verify user actions
• add snowplow event for tracking the closing of the alert
• update tests

Screenshots or screen recordings

Tracking information:

export const trackAgentSecurityTabAlert = {
  category: 'Vulnerability_Management',
  action: 'agent_security_tab_alert',
};

Before	After

Up close

How to set up and validate locally

1. Ensure your GDK has a GitLab Ultimate license
2. Ensure your GDK is connected to the GitLab Runner
3. Follow these docs to set up the kubernetes agent
4. Navigate to a project
5. Link the agent to a project
6. Enable the :cluster_vulnerabilities feature flag
7. Navigate to the agent
8. View the vulnerabilities

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 #351622 (closed)