Reorganize issues and merge request feature specs in the same folder

What does this MR do?

This reorganizes issues and merge request feature specs in the same folder so that we can de-duplicate/improve/delete them more easily in the future.

Does this MR meet the acceptance criteria?

• [-] Changelog entry added, if necessary
• [-] Documentation created/updated
• [-] Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides