Cross-tenant URL signing
Steps to reproduce
Both the URL Singing REST Endpoint and the External API - Security Endpoint can be used by authorized users to sign URLs.
Since signing keys do not belong to specific organizations (tenants), any authorized user can indirectly use any signing key.
With other words: An authorized user of organization A can sign URLs of organization B that allows organization A to access distribution artefacts of organization B.
Yes, it is ready for review.