tracing: add native support sending traces to the Jaeger

[andrewtar]

Currently, the cockroach db can send traces only in Zipkin format to Jaeger, as described here. This means that the database is only currently able to send traces to Jaeger collector, not Jaeger agent. There are two problems with this:

• Zipkin uses HTTP protocol to send traces, which is very inefficient compared to UDP.
• Sending traces to Jaeger collector breaks the canonical Jaeger deployment architecture. In our case, we have to send traces from cockroach to Jaeger collector, while all our other services send traces to Jaeger agent.

It would be better if cockroach had a native Jaeger support and was able to send traces to Jaeger agent over UDP.

Jira issue: CRDB-4959

Epic CRDB-20779

[knz]

cc @andreimatei

[github-actions[bot]]

We have marked this issue as stale because it has been inactive for 18 months. If this issue is still relevant, removing the stale label or adding a comment will keep it active. Otherwise, we'll close it in 5 days to keep the issue queue tidy. Thank you for your contribution to CockroachDB!

[knz]

I think @andreimatei is currently working on this