### Feature and motivation

Be able to link custom OpenTelemetry tracing with the default Selenium grid tracing. See for e.g. https://github.com/llatinov/selenium-observability-java/blob/324b500316be34f5f1426720353d0c4e2e8b5a89/selenium-tests/src/main/java/com/automationrhapsody/observability/TracingWebDriver.java#L81 
It will be useful if I am able to pass my Span as a parent span of Selenium's RemoteWebDriver tracing, so I can trace my actions with corresponding grid actions.

### Usage example

Implement a custom tracing that monitors the tests. It will be of great help to be able to make the default server/grid tracing a child of the custom tracking. In this case, users can monitor how a click of a button in their tests links to grid performance.
package org.openqa.selenium.remote.tracing.empty;
import org.openqa.selenium.remote.tracing.Propagator;
import org.openqa.selenium.remote.tracing.TraceContext;
import org.openqa.selenium.remote.tracing.Tracer;
public class NullTracer implements Tracer {
  @Override
  public TraceContext getCurrentContext() {
    return new NullContext();
  }
  @Override
  public Propagator getPropagator() {
    return new NullPropagator();
  }
}