cloud events, e2e latency, az monitor reporting

1. add metrics reporting to azure monitor (using appinsights instrume…

…ntation key)

2. have consistent metric across publisher/subscriber
3. add e2e latency Metric
4. add cloud event publisher
5. remove newtonsoft, replace with System.Text.Json + BodyReader buffering
6. add metrics context handling to isolate different kinds of runs in the dashboards
7. Add flag to log payload in Subscriber
8. Make thread safe random less cryptic