### 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.
}
  @Test
  public void currentSpanIsKeptOnTracerCorrectlyBetweenThreads() throws ExecutionException, InterruptedException {
    List<SpanData> allSpans = new ArrayList<>();
    Tracer tracer = createTracer(allSpans);
    try (Span parent = tracer.getCurrentContext().createSpan("parent")) {
      assertThat(parent.getId()).isEqualTo(tracer.getCurrentContext().getId());
      Future<?> future = Executors.newSingleThreadExecutor().submit(() -> {
        Span child = null;
        try {
          child = parent.createSpan("child");
          assertThat(child.getId()).isEqualTo(tracer.getCurrentContext().getId());
        } finally {
          assert child != null;
          child.close();
        }
        
        assertThat(parent.getId()).isNotEqualTo(tracer.getCurrentContext().getId());
        assertThat(child.getId()).isNotEqualTo(tracer.getCurrentContext().getId());
        assertThat(tracer.getCurrentContext().getId()).isNotNull();
      });
      future.get();
      assertThat(parent.getId()).isEqualTo(tracer.getCurrentContext().getId());
    }
  }
  @Test
  public void cleverShenanigansRepresentingWhatWeSeeInTheRouter() {
    List<SpanData> allSpans = new ArrayList<>();
    Tracer tracer = createTracer(allSpans);
    CombinedHandler handler = new CombinedHandler();