http2: add req and res options to server creation

Add optional Http2ServerRequest and Http2ServerResponse options
to createServer and createSecureServer. Allows custom req & res
classes that extend the default ones to be used without
overriding the prototype.

PR-URL: https://github.com/nodejs/node/pull/15560


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>