http2: refactor error handling

This changes the error handling model of ServerHttp2Stream,
ServerHttp2Request and ServerHttp2Response.
An 'error' emitted on ServerHttp2Stream will not go to
'uncaughtException' anymore, but to the server 'streamError'.
On the stream 'error', ServerHttp2Request will emit 'abort', while
ServerHttp2Response would do nothing

See: https://github.com/nodejs/node/issues/14963

PR-URL: https://github.com/nodejs/node/pull/14991


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