Update Options to hide traceparent and tracestate

[azabbasi]

This change will render certain options look empty to users so we are removing them from the API signatures.

We have the option to just mark some of the options internal and do not implement any overrides in customized classes, but that will result in TraceParent and TraceState have the incorrect naming format : Tracestate, Traceparent

[drwill-ms]

I really don't like the regions for internal properties, but other than that, looks good.

[tg-msft]

If you're making the Options classes internal, do they get set as headers by the generated code? Does that conflict with https://github.com/Azure/azure-sdk-for-net/blob/master/sdk/core/Azure.Core/src/Pipeline/Internal/RequestActivityPolicy.cs? // cc @pakrym as the expert here

[tg-msft]

Yeah, that was my advice because the RequestActivityPolicy sets them automatically. However it won't replace them if already set. I just want to double check the generated code doesn't cause a problem. If it does, we could also just yank all the traceparent/tracestate headers from your swagger with a README transform in our repo.

[timtay-microsoft]

it won't replace them if already set.

We shouldn't be passing down any values for these to the generated code, so we should be fine here

[pakrym]

FYI #16318 (comment) coming