Delete inaccessible Security Report Code

What does this MR do?

Remove outdated Secure business logic from the frontend.

Part of #196719 (closed).

Screenshots

N/A: no UI changes.

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