Sort vulnerability links and identifiers

What does this MR do?

Adds sorting to the Vulnerabilities[].Links and Vulnerabilities[].Identifiers fields, so we can provide deterministic report output, and remove sorting of these fields from the integration-test.

What are the relevant issue numbers?

Move sorting from integration-test Comparable m... (gitlab-org/gitlab#383219) • Unassigned

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Ensure the report version matches the equivalent schema version
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer