Make hashed storage required for Design Management

What does this MR do?

This MR makes hashed storage a requirement for Design Management.

This is in order for us to handle the problem of legacy storage being incompatible with moving the design repository when the project repository moves on disk.

• #13428 (closed)

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

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