http: process 100, 102-199 according to specs.

Adding ServerResponse.writeProcessing to send 102 status codes.

Added an `'information'` event to ClientRequest to handle
1xx status codes except 101 Upgrade.
101 Upgrade is excluded due to its non-informational
processing according to RFC7231, Section 6.2.2.

This affects several modules downstream that use the http
module, e.g., node-fetch, all of whom violate HTTP RFCs
due to this module. As such, this could introduce a
breaking change for downstream if HTTP standards were
ignored in an ad-hoc fashion.

See also RFC2518 RFC8297.

PR-URL: https://github.com/nodejs/node/pull/18033


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>