feat: report.FilterDisabledRules should filter both vulnerabilities and primary_identifiers

What does this MR do?

With the rollout of gitlab-org/gitlab#368284 (closed) there's a nuance in terms of rule removal that we missed. Custom rulesets disable rules by removing from Vulnerabilities but do not affect Scan.PrimaryIdentifiers which was missed previously. As such, it is not correctly filtering out the disabled values.

What are the relevant issue numbers?

Addresses gitlab-org/gitlab#398809 (closed)

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