Bug 195 | Provide infotip on how to calculate CVSS score

[TechnicalDoctor]

Summary of Changes:

1. Added Infotip Icon next to Official CVSS Score Label: Modified the HTML in
   lib/src/api/Vulnerability/render-vulnerabilities.js to include a clickable, styled infotip icon (ⓘ) inline with the
   label.
2. Hover Tooltip: Integrated with the app's existing .tooltip CSS class so hovering over the icon displays a clean,
   user-friendly bubble stating "Click here to calculate CVSS score".
3. Secure External Navigation: Configured the click action on the icon to safely invoke window.vulnerabilities.openURL
   using the official FIRST.org CVSS 3.1 calculator link (https://www.first.org/cvss/calculator/3.1), ensuring it opens
   inside the user's default web browser instead of hijacking the Electron frame.
4. HTML Correction: Rectified malformed tag nesting in the score denominator (changed /10 to
   /10).
5. Testing & Validation:
   • Installed dependencies and executed the complete test suite in lib/.
   • All 311 tests passed successfully with zero regressions!