### 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.
String arrayKey = "longArray";
    String varArgsKey = "longVarArgs";
    long[] longArray = new long[]{400L, 200L};
    AttributesBuilder attributes = Attributes.builder();
    attributes.put(arrayKey, longArray);
    attributes.put(varArgsKey, 250L, 5L);
    try (Span span = tracer.getCurrentContext().createSpan("parent")) {
      Map<String, EventAttributeValue> attributeMap = new HashMap<>();
      attributeMap.put(arrayKey, EventAttribute.setValue(longArray));
      attributeMap.put(varArgsKey, EventAttribute.setValue(250L, 5L));
      span.addEvent(event, attributeMap);
    }
    assertThat(allSpans).hasSize(1);
    List<EventData> timedEvents = allSpans.get(0).getEvents();
    assertThat(timedEvents).element(0).extracting(EventData::getName).isEqualTo(event);
    assertThat(timedEvents.get(0).getAttributes()).isEqualTo(attributes.build());
  }
  @Test
  public void canCreateASpanEventWithStringAttribute() {
    List<SpanData> allSpans = new ArrayList<>();
    Tracer tracer = createTracer(allSpans);
    String event = "Test event";
    String attribute = "testString";
    String attributeValue = "attributeValue";
    AttributesBuilder attributes = Attributes.builder();
    attributes.put(attribute, attributeValue);
    try (Span span = tracer.getCurrentContext().createSpan("parent")) {
      Map<String, EventAttributeValue> attributeMap = new HashMap<>();
      attributeMap.put(attribute, EventAttribute.setValue(attributeValue));
      span.addEvent(event, attributeMap);