No-op span ID generation #159
Description
- If the span is not sampled, we shouldn't create a real span.
- If the span is sampled, and there is just the API package (not the SDK package), the outgoing span (SpanKind = Server) should generate a new span id (but not a new trace id) in order to be compliant with W3C TraceContext. All the in-process spans should be dummy spans (zero span id).
- If the span is sampled, and there is SDK package, everything should just work, and compliant with W3C TraceContext.
- Integrations should not try to tell if SDK exists or not, integrations should not try to tell if SDK exists or not and perform special operations.