http: fix parsing of binary upgrade response body

Fix a bug where a connection upgrade response with a Transfer-Encoding
header and a body whose first byte is > 127 causes said byte to be
dropped on the floor when passing the remainder of the message to
the 'upgrade' event listeners.

Fixes: https://github.com/nodejs/node/issues/17789

PR-URL: https://github.com/nodejs/node/pull/17806
Fixes: https://github.com/nodejs/node/issues/17789


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>