Replace Opencensus with OpenTelemetry

[Thorsten Essig]

The official successor of Opencensus is https://opentelemetry.io/.

Start with a new repo first.

Todos Tracing:

• Deprecate opencensus and use opentelemetry
• Integrate Tracing
• Integrate Metrics
• use otel-bridge for backwards compatibilityhttps://pkg.go.dev/go.opentelemetry.io/otel/bridge/opencensus
• Provide integration like gin: https://pkg.go.dev/go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin

Follow up Topics:

• Evaluate Logging

[Bastian]

Simple answer: yes.

Also if we can get the logging in here as well, it'd be even nicer. But maybe that needs a flamingo v4?