Add opentemeletry-go tracing support on top of `opentracing`.

[bwplotka]

https://github.com/open-telemetry/opentelemetry-go/blob/master/api/trace/api.go

[bwplotka]

Actually the current idea is to support both interfaces (: in v2 branch. See: https://github.com/grpc-ecosystem/go-grpc-middleware/issues/275

[bwplotka]

Acceptance Criteria:

• Users can use tracing interceptor with opentelemetry-go APIs too.

NOTE:

• Opentelemetry project is not Stable yet, APIs are changing that's why another provider and not replacing opentracing

OpenTelemetry is bit confusing, there are many abstractions. In practice I found it useful to create simpler wrapper for thousands of modules they have: * I would suggest using some abstraction like https://github.com/AnaisUrlichs/observe-argo-rollout/tree/main/app/tracing

I don't think we need to use this code, but we might want to add that for testing, or your own experimentation purposes (who ever is on this issue)

[bwplotka]

This is easier than we thought thanks of OpenTelemetry.

https://github.com/grpc-ecosystem/go-grpc-middleware/pull/543 changes v2 to remove tracing completely, since two interceptors can be used together with other middlewares:

• Tracing:
  • (external) otelgrpc - official OpenTelemetry tracing interceptors as used in example.
  • (external) opentracing - deprecated OpenTracing client-side and server-side interceptors if you still need it!