Resolve "Implement GraphQL Startup.js for Design Management app"

What does this MR do?

Currently, the Design Management application is the last piece to load on the Issue page, causing Last Contentful Paint to be delayed until ~2600ms (gitlab.com). This MR implements a preloading of the designs with GraphQL Startup.js to speed things up.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• 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
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Related to #263109 (closed)