Migrate Security Findings Webview from HTML to Vue

Description

This migrates the webview for security findings to a vue app.

Related Issues

Resolves #1010 (closed)

How has this been tested?

1. Checkout an open MR with security findings
   1. Example: gitlab-ui!3765 (merged) or another open MR in the gitlab-ui project should have security findings listed
2. Reload the extension
3. It should list down the vulnerabilities under "Security scanning" tab.
4. There're no user facing changes to this MR

Screenshots (if appropriate):

No visual changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation
• Chore (Related to CI or Packaging to platforms)
• Test gap