Tracing: support jaeger-agent tracer

*Title*: *One line description*
When we used envoy and jaeger together, we found that envoy does not support sending data directly to jaeger-agent.
*Description*:
>Describe the the desired behavior, what scenario it enables and how it
would be used.

[optional *Relevant Links*:]
>Any extra documentation required to understand the issue.
https://github.com/jaegertracing/jaeger-client-cpp
https://www.jaegertracing.io/docs/1.22/architecture/