add opentelemetry tracing

[dmah42]

https://docs.rs/tracing-opentelemetry/latest/tracing_opentelemetry/

we should, either by default or as an option, have opentelemetry tracing enabled

[MatonAnthony]

Does this mean we would replace the tracing crate by tracing_opentelemetry?

Update: Nevermind, we have to add the tracing_opentelemetry. Parts of the code already have the [#instrument], so it should work out of the box, I am looking at how to test it :)