Get one-time-scans working with Nats

[sleepycat]

We disabled Trackers one-time-scan functionality when we switched over to nats. With scanners working and nats a success, we need to go back and rework the one-time-scan logic to use events and get that working again.

• [ ] Switch the server sent events (demo, library)
• [ ] Generate events from scanners
• [ ] Capture events and send using GraphQL

[CADbryon]

Targeted for Dec/Jan timeframe.