Get opentelemetry trace id from request headers instead of creating a new trace

[ptanov]

Feature request

Currently a new trace is created per each HTTP request. It would be useful if trace is get (if available) from the request using traceparent header as defined in https://opentelemetry.io/docs/specs/otel/context/api-propagators/#propagators-distribution https://www.w3.org/TR/trace-context/

In this way you will be able to trace the request through microservice invocations.

Motivation

I want to track the request using opentelemetry starting from frontend, backend and then TGI

Your contribution

I don't have enough understanding of TGI code