Fix security dashboard breadcrumb on vulnerability details page

What does this MR do?

When viewing the vulnerability details for a project, there is a breadcrumb link at the top:

This MR fixes the following issues:

1. The breadcrumb text should be Vulnerability Report instead of Security Dashboard.
2. The left navbar item for Vulnerability Report should be highlighted when on the vulnerability details page.
3. Clicking on the breadcrumb link should link to Vulnerability Report, not Security Dashboard.

Before	After

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done