Here is how response headers are logged for HTTP/1.1 and HTTP/2

The first line is for an intermediate response (102), the second for a final response(200)

----------------- http/1.1 --------------------------------
INFO: HEADERS: RESPONSE HEADERS:


INFO: HEADERS: RESPONSE HEADERS:
    content-length: 11

----------------- http/2 --------------------------------
INFO: HEADERS: RESPONSE HEADERS:
    :status: 102

INFO: HEADERS: RESPONSE HEADERS:
    :status: 200
    content-length: 11

--------------------------------------------------------------------------

I'd suggest that we add the Response::toString for HTTP/1.1, that will contain the status + URI, and the streamId for HTTP/2, which will help corelate with the request headers (the streamId is already logged with the
request headers)

For instance, something like below would be an improvement:

----------------- http/1.1 --------------------------------
INFO: HEADERS: RESPONSE HEADERS (GET http://127.0.0.1:59767/test/hello) 102 HTTP_1_1 Local port: 59772:


INFO: HEADERS: RESPONSE HEADERS (GET http://127.0.0.1:59767/test/hello) 200 HTTP_1_1 Local port: 59772:
    content-length: 11

----------------- http/2 --------------------------------
INFO: HEADERS: RESPONSE HEADERS (streamid=1):
    :status: 102

INFO: HEADERS: RESPONSE HEADERS (streamid=1):
    :status: 200
    content-length: 11