[License Complaince MR Widget Extension] - Frontend - License compliance V1

This issue is to track the engineering efforts of the License compliance widget using the new Merge request reports framework.

Resources

• Related UX Issue
• Figma Design Specifications
• Merge request reports framework

Implementation Plan

• Changes must live behind the refactorMrWidgetsExtensions/refactorMrWidgetsExtensionsUser featureFlag
• Add new MR widget extension taking !70993 (diffs) as an example
• reimplement all functionality the License Compliance MR currently has in the extension
  • collapsed state
  • uncollapsed state
  • uncategorized Licenses
  • allowed Licenses
  • denied Licenses
• be aware that merge request widget currently does not support any actions on the first level, tracked in #341048 (closed) and this MR can't be merged until this is supported.

Testing

SET shall update existing BrowserUI License compliance tests, add new tests to accommodate new UI functionality.