http: expose http.validate-header-name/value

The use-case is for any framework that provides user mw a response
replacement, that collects the desired response state, and applies them
only on conclusion. As such a framework, I'd want to validate the
header names and values as soon as the user-code provides them.
This - to eliminate errors on response-send time, and provide developer
stack trace that contains the line that submits the offending values.

PR-URL: https://github.com/nodejs/node/pull/33119


Reviewed-By: Anna Henningsen <anna@addaleax.net>