Extract incoming Http request headers to span attributes #17452
Description
Problem Statement
Currently, we extract request data and put it onto the request event context. In the future, we should extract headers to span attributes directly, to no longer rely on contexts.
Solution Brainstorm
This is likely quite easy since for now, all we have to do is attach the same headers we already put onto the request context into span attributes. The span attributes must follow the request.headers.[key] semantic convention. TBD: Do we need to flatten the array into a string?