Support the new TraceId and SpanId in Serilog

[lindeberg]

Serilog 3.1 adds first-class support for TraceId and SpanId:
serilog/serilog#1955

Each sink has to implement this.

[mishamyte]

Thanks for the idea.

Looks like a wonderful feature. But according to the info, it will be the breaking change.
So it should be decided should the new release would be created with a dep from the Serilog 3.1. It looks pretty logical to put in into a v9 roadmap, because for me the breaking change should occur only in major releases. And a lot of people, who use that sync, have no possibility to update to the latest Serilog in their projects.

So I suggest to put that into a v9 roadmap