http: support readable hwm in IncomingMessage

This commit causes http.IncomingMessage instances to set their
readableHighWaterMark value the same value used in the underlying
socket.

PR-URL: https://github.com/nodejs/node/pull/30135
Fixes: https://github.com/nodejs/node/issues/30107


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>