Usage data design management

What does this MR do?

This MR adds usage counters for designs, as per https://gitlab.com/gitlab-org/gitlab-ce/issues/63885

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry for user-facing changes, or community contribution. Check the link for other scenarios.
• 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

/cc @dsatcher @.luke @phikai