HTTPX instrumentation - document how to log request payload and response on response_hook

Is your feature request related to a problem?
After reading the httpx instrumentation docs it is clear I need a response_hook and how to use it. But it has no example how to really use this with the span, request, response attributes to log the payload from request and response.

After digging into __init__() I see both ResponseInfo and RequestInfo have a stream property that could potentially be the solution, but each of them are a different type:

class RequestInfo(typing.NamedTuple):
....
typing.Optional[
        typing.Union[httpx.SyncByteStream, httpx.AsyncByteStream]
    ]

class ResponseInfo(typing.NamedTuple):
...
    stream: typing.Iterable[bytes]

In those cases it is not very clear an easy way to log the information from the payload.

Describe the solution you'd like
A simple example of response_hook in the docs with logging of payload of request and response.

Start with the linked HTTPX instrumentation documentation and inspect init(), including the RequestInfo and ResponseInfo stream properties. Document a response_hook example that shows how to access the span, request, and response and log request and response payloads, while clarifying the differing stream types.