http2: do not emit our own close emit in Http2Stream

Streams were recently updated to emit their own close event. The
Http2Stream was an exception because it included the close argument
with the close event. Refactor that to use the built in close.

PR-URL: https://github.com/nodejs/node/pull/19451


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>