test: http2Stream redundant shutdown and single cb

PR-URL: https://github.com/nodejs/node/pull/15612
Refs: https://github.com/nodejs/node/issues/14985


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>