Add open telemetry to Azure.AI.Inferencing

[nick863]

In this PR we are adding the Open Telemetry in Azure.AI.Inferencing.

[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

Azure.AI.Inference

[jsquire]

@lmolkova: If you would be so kind as to take a look at the OTel bits, it would be appreciated.

[dargilco]

Does the NuGet now declare a new dependency on one or more tracing packages, even if I don't want to turn on tracing? If so, what is the total size of these additional packages?

[nick863]

Does the NuGet now declare a new dependency on one or more tracing packages, even if I don't want to turn on tracing? If so, what is the total size of these additional packages?

The Open Telemetry is not a dependency of Azure.AI.Inference. In this PR we create an Activity and if user created a Listener from scratch (as we did in E2E tests) or the Tracer and Meter providers, it will log the metrics and send it to listener. This part is done by the standard .NET library System.Diagnostics. The open telemetry is in the user space, user will need to install the appropriate dependencies separately. We only add the OpenTelemetry as a test dependency, only in test purposes.