Resolve "Shortest path not displayed in vulnerability page"

What does this MR do and why?

• Fixes an issue that prevents certain generic vulnerability report types from being rendered
• Small refactor to use primitive constants instead of an object to define the report types

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

1. Set up https://gitlab.com/gitlab-org/security-products/tests/js-yarn locally
2. Run a pipeline against master
3. Navigate to the project's vulnerability report
4. Open finding with the title "Insufficient Entropy" and verify that the "Evidence" section renders as the screenshot above
5. Navigate to the pipeline report and repeat step 4

Related to #438550 (closed)