Updated value stream dashboard vulnerability links

What does this MR do and why?

Updated the Critical / High vulnerabilities over time links:

• update the "drill down" links to include the severity level when redirecting to the vulnerability reports
• update the docs tooltip links

Screenshots or screen recordings

Critical	High	Docs

How to set up and validate locally

You will need a GitLab Ultimate license

1. Create a group
2. Seed cycle analytics data
3. Seed dora metrics data
4. Seed MRs in the merged state - see this note for some hints
5. Visit the Value streams dashboard

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 #411196 (closed)