Add dev design support (seeds and rake tasks)

What does this MR do?

This MR adds development support for EE and specifically design management models, in particular it adds:

• a Rake task to load a license, useful when re-seeding the DB.
• a Rake tast that enables design management
• a seed file that adds designs to an issue.

This prevents a lot of tedious manual setup when working on design management.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry not needed here
• 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

This does not affect user facing code, only aiming to improve the development environment.

For testing, this actually improves the current state by making manual testing easier. By adding a seed file, we also get better test coverage of adding designs since this seed will be run by the CI.

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.