Remove parsed_license_report feature flag

What does this MR do?

Remove parsed_license_report feature flag

This also removes the redundant head/base path handling, and cleans up the display logic for the license report MR widget.

Part of Remove parsed_license_report flag from front end code.

WIP

This is marked WIP, as it depends on !24204 (merged).

Screenshots

N/A; no UI changes, this is a backstage change only.

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