BTE OTel not properly carrying context between POST and EXEC

[tokebe]

NCATSTranslator/Feedback#925

You can see in this example here that BTE does carry the initial traceparent in its POST capture behavior, and here that it does trace well when executing, however the execution spans do not end up as children to the post spans.

BTE does currently pass traceparent information to execution threads, but something in the span configuration causes the context to be lost, making these appear as separate operations. Perhaps re-naming EXEC spans to match the POST spans?

Either way, more investigation and tinkering is required.