Issue #3377657 by catch, mondrake: Add database query spans to otel traces

        ->setAttribute('http.url', $url)

        ->startSpan();

      $first_byte_span->end($response_wall_time);

      $collection = \Drupal::keyValue('performance_test');

      $performance_test_data = $collection->get('performance_test_data');

      $query_events = $performance_test_data['database_events'] ?? [];

      foreach ($query_events as $key => $event) {

        // Use the first part of the database query for the span name.

        $query_span = $tracer->spanBuilder(substr($event->queryString, 0, 64))

          ->setStartTimestamp((int) ($event->startTime * $nanoseconds_per_second))

          ->setAttribute('query.string', $event->queryString)

          ->setAttribute('query.args', var_export($event->args, TRUE))

          ->setAttribute('query.caller', var_export($event->caller, TRUE))

          ->startSpan();

        $query_span->end((int) ($event->time * $nanoseconds_per_second));

      }

      $lcp_timestamp = NULL;

      $fcp_timestamp = NULL;

      $lcp_size = 0;