Moves the license compliance reports to the Backend

What does this MR do?

This MR moves the license compliance reports parsing from the frontend to the backend.

It does both the pipelines and the merge request widget in one go as they're both tightly coupled at the moment.

It's all behind the feature flag parsedLicenseReport

https://youtu.be/bcfj3dz-Zyg

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Performance 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

Closes #32030 (closed)