Resolve "Extract EE specific files/lines for spec/controllers/admin"

Extract EE specific files/lines for spec/controllers/admin to EE directory.

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

Closes #6569 (closed)