Attestation Authority Response
Note kind that represents a logical attestation "role" or "authority". For example, an organization might have one AttestationAuthority
for "QA" and one for "build". This Note is intended to act strictly as a grouping mechanism for the attached Occurrences (Attestations). This grouping mechanism also provides a security boundary, since IAM ACLs gate the ability for a principle to attach an Occurrence to a given Note. It also provides a single point of lookup to find all attached Attestation Occurrences, even if they don't all live in the same project.