ensure certificate signing date is included

I ran a photo created in proofmode-rust c2pa through the c2pa-js example "active manifest" demo, and this is what was displayed:

It taps into these fields: title: activeManifest.title, format: activeManifest.format, claimGenerator: activeManifest.claimGenerator.split('(')[0]?.trim(), producer: selectProducer(activeManifest)?.name ?? 'Unknown', thumbnail: <img src="${url}" class="thumbnail" />, ingredients: (activeManifest.ingredients ?? []) .map((i) => i.title) .join(', '), signatureIssuer: activeManifest.signatureInfo?.issuer, signatureDate: activeManifest.signatureInfo?.time ? parseISO(activeManifest.signatureInfo.time).toString() : 'No date available', };

Seems like we should add a timestamp to the signatureInfo?

also producer name too? maybe that is the PGP key Id?