Surface opentelemetry Jaeger data in the UI

[vazirim]

Is your feature request related to a problem? Please describe.

Currently the actual input to an LLM appears in the opentelemetry data and can be seen in the Jaeger interface. It would be good to unify that with the UI and show that information in the UI as well.

Describe the solution you'd like

Describe alternatives you've considered

Additional context

[vazirim]

Figure out how to make the litellm callback work.

[esnible]

@starpit Is there a way we can work together on this?

LiteLLM's callbacks are explained at https://docs.litellm.ai/docs/observability/custom_callback . One step we could take is to try to attach the callbacks and their parameters as "messages" to the trace.

However, that would mean deeper connections with the internal model of LiteLLM. For #532 we should consider defining a general way for PDL to indicate LLM parameters and LLM responses.