Add status groups to license-compliance MR widget

What does this MR do?

This MR groups licenses within the license-compliance MR widget by their status. It adds a header and description for each group, to provide context to the user.

It also changes a vue-spec to use vue-test-utils.

Screencaptures

before	after
before	after_v2

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

Related to #12530 (closed)