Support W3C Trace Context headers

[yurishkuro]

https://github.com/w3c/distributed-tracing

• Go client
• Java client Add W3C TraceContext codec/propagation  jaeger-client-java#694
• Node client
• Python client Feat request: Support W3C Trace Context header jaeger-client-python#284
• C++ client w3c trace context propagation support  jaeger-client-cpp#160
• C# client Support W3C Trace Context headers jaeger-client-csharp#90

[trevnet]

+1 waiting on this so I can use jaeger for my services

[grounded042]

@yurishkuro are we also wanting to support the correlation context headers defined in that repo or just the trace context headers?

[yurishkuro]

Correlation header is currently not finalized as people have disagreements. So I would skip it for now. It means that we still need another way of propagating the baggage.

[grounded042]

so when we add Jaeger baggage in as long as the other Jaeger clients implement the same propagation method for baggage for W3C we'll be good, but until they finalize the correlation header technically no one else will be able to use that baggage. I'm fine with that - we just have to make sure all the Jaeger clients implement baggage handling for W3C the same.

[yurishkuro]

Per #3362, we're sunsetting Jaeger clients. OpenTelemetry already supports W3C.