fix: add Referrer-Policy header check and update description

[balaakasam]

Description

Adds a missing Referrer-Policy header check to the existing Multiple Security Header Check script and updates the metadata description to include it in the list of checked headers.

Changes

• Added Referrer-Policy to the metadata description list
• Added check for missing Referrer-Policy header with appropriate alert name, description, and solution

Why

The Referrer-Policy header is a modern security header recommended by OWASP and included in the OWASP Secure Headers Project. It was missing from this script while all other major security headers were already covered.

References

• https://owasp.org/www-project-secure-headers/
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy

[psiinon]

Checkmarx One – Scan Summary & Details – b5001f10-97a8-4673-992d-676147667dba

Great job! No new security vulnerabilities introduced in this pull request

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[kingthorin]

Needs a spotlessApply.
Also the new addition may as well follow the array mechanism the original code already established for alert details.