What is the current usage of the span in the query option

[yzhuang93]

I saw today we have this WithSpan function: https://github.com/ClickHouse/clickhouse-go/blob/main/context.go#L68
Are we using this to stitch client span with clickhouse server span for tracing purposes? Or just save the span to the clickhouse.

I am asking this because usually opentelemetry will need the propagator to inject or extract the span context instead of directly saving it under a struct or so.

Also, I believe in golang we'd better use the context itself to pass the span context as when starting a span, the span context should already be included in the golang context, directly passing the span context might not be a good way.