Azure Event Hubs client library samples for JavaScript

[core-https] Update runtime dependency "https-proxy-agent" (#9162)

- Remove unnecessary dev dependency from "@azure/event-hubs" and "@azure/service-bus"
  - No longer needed since the samples have been moved to their own package
- Update runtime dependency used by samples to match "@azure/core-https"
- Update dev dependency used by "@azure/event-processor-host" (samples still use the runtime package.json)