Move Design Management request specs to FOSS

What does this MR do?

Now that the views have been moved to FOSS for Design Management in !31309 (merged) we can move the request specs.

This change is part of #212566 (closed) to move all Design Management code to FOSS.

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