Feature/traces sampler

[openPablo]

Issue describing the changes in this PR

resolves #11496

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[RohitRanjanMS]

Hi @openPablo , Thank you for taking the time to submit this PR. I agree that sampling is essential, particularly in high-volume scenarios. I believe the OpenTelemetry SDK should respect OTEL_TRACES_SAMPLER and OTEL_TRACES_SAMPLER_ARG directly, without requiring us to manually read the environment variables and configure the sampler ourselves

https://github.com/open-telemetry/opentelemetry-dotnet/blob/a338c96436fd3f2a890df587641a99bd2c0e6372/src/OpenTelemetry/Trace/TracerProviderSdk.cs#L404

[openPablo]

Hey @RohitRanjanMS, thank you for taking the time to read through my feature request and PR.

I'm not sure I understand you correctly.

Should I edit the code so that it works with environment variables, without manually setting config flags?
Or did you mean to say it's already working like expected?