http2: add writable* properties to compat api

added writableHighWaterMark, writableLength, and writableFinished
properties with test.

Refs: https://github.com/nodejs/node/issues/29829

PR-URL: https://github.com/nodejs/node/pull/33506


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>