Resolve "Test authorizations in GraphQL Mutations"

What does this MR do?

After !30958 (merged), we can now test that mutations are using the correct authorizations.

Also, update existing GraphQL single liners to use the specify syntax.

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

Closes #216516 (closed)