Implement IsSampled for OpenTelemetry bridgeSpanContext

[pijusn]

This is a PR in response to issue #3532 .

IsSampled is not exposed by OpenTracing but its implementations did (at least some; sometimes called differently; Jaeger does). Cosidering that in OpenTracing this information was accessed by casting types, this implementation is no different - instances can be casted to an interface with expected methods in order to access it. Once moved to the bridge, eventually bridge can be dropped and this information would continue being exposed through the OpenTelemetry's span context.

Resolves #3532

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: pijusn / name: Pijus Navickas (752c12a)

[codecov]

Codecov Report

Merging #3570 (b450b22) into main (99ec432) will increase coverage by 0.0%.
The diff coverage is 100.0%.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3570   +/-   ##
=====================================
  Coverage   81.6%   81.7%           
=====================================
  Files        166     166           
  Lines      12442   12444    +2     
=====================================
+ Hits       10162   10168    +6     
+ Misses      2065    2061    -4     
  Partials     215     215           

Impacted Files	Coverage Δ
bridge/opentracing/bridge.go	63.9% <100.0%> (+0.1%)	⬆️
bridge/opentracing/internal/mock.go	67.0% <100.0%> (ø)
sdk/trace/batch_span_processor.go	81.9% <0.0%> (+1.7%)	⬆️

[MrAlias]

Please update the README with a section on how the sampled state can be accessed. Additionally, it might be worth adding an example test that accesses this method.

[pijusn]

I'm not sure example test is worthwhile here. It would contain a lot of boilerplate just to set it up and then very trivial example. Also, there is no documentation for it to be attached to. I would skip it for this component. I think example in the README should be enough (given that this is the documentation for this package).

If you do feel strongly about it, I can add it still. Let me know.

[pijusn]

@MrAlias could you see the latest changes? Would be much appreciated.

[pijusn]

Merged your suggestions, moved note to the unreleased, added PR ID to the note and merged the main branch into the PR. Should be up-to-date now.

[pijusn]

I merged main into this branch to resolve the conflict. Do you have any timeline when it could be merged (no merge rights over here, it will have to be you)? It conflicts every time something gets appended to the CHANGELOG.

[MrAlias]

This still needs another review from someone else before it is ready to merge.

[pijusn]

Thank you for reviewing the PR. I updated the branch to the latest main. It has no conflicts at the moment. I do not have the permissions required for the merge. I hope it gets merged soon 🤞🏻