http2: fixes error handling

There should be no default error handling when using Http2Stream.
All errors will end up in `'streamError'` on the server anyway,
but they are emitted on `'stream'` as well, otherwise some error
conditions are impossible to debug.

See: https://github.com/nodejs/node/pull/14991

PR-URL: https://github.com/nodejs/node/pull/19232


Reviewed-By: James M Snell <jasnell@gmail.com>