This commit renames the tracing to telemetry.tracing in both xpack/APM and elasticserach's org.elasticsearch.tracing.Tracer (the api)
the xpack/APM is renamed as follows:
org.elasticsearch.telemetry.apm - the only exported package
org.elasticsearch.telemetry.apm.settings - APMSettings
org.elasticsearch.telemetry.apm.tracing - APMTracer
org.elasticsearch.tracing.Tracer is moved to org.elasticsearch.telemetry.tracing.Tracer (responsible for majority of the changes in this PR)
This commit changes the ActionModules to allow the RestController to be
provided by an internal plugin.
It renames `RestInterceptorActionPlugin` to `RestServerActionPlugin`
and adds a new `getRestController` method to it.
There may be multiple RestServerActionPlugins installed on a node, but
only 1 may provide a Rest Wrapper (getRestHandlerInterceptor) and only 1
may provide a RestController (getRestController).
Przemyslaw Gomulka
Tim Vernum