Export design management data with project export
What does this MR do?
This MR allows Design Management data to be included in the project import/export.
A separate MR https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14700 contains changes to support the project's design repository. This MR will remain a
WIP: until !14700 (merged) is merged into this MR.
Does this MR meet the acceptance criteria?
- 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 #11090 (closed)