Neo4j/cypher Backend Tech Debt

[jeffmendoza]

We have updated some types in the inmem backend, and have left the neo4j backend behind. Let's keep a list here to remember:

• IsOccurrence: subject type options validation needs to be updated
• HasSBOM: subject type options validation needs to be updated
• CertifyBad: subject type options validation needs to be updated
• CertifyGood: subject type options validation needs to be updated
• isVuln: subject type options validation needs to be updated
• CertifyVEX: subject type options validation needs to be updated
• CertifyVuln: subject type options validation needs to be updated
• HasSLSA: changed from PackageSourceOrArtifact to only Artifact, needs update
• GHSA: update to not have root nodes
• OSV: update to not have root nodes
• CVE: update to not have root nodes