stream: 'readable' have precedence over flowing

In Streams3 the 'readable' event/.read() method had a lower precedence
than the `'data'` event that made them impossible to use them together.
This make `.resume()` a no-op if there is a listener for the
`'readable'` event, making the stream non-flowing if there is a
`'data'`  listener.

Fixes: https://github.com/nodejs/node/issues/18058

PR-URL: https://github.com/nodejs/node/pull/18994


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>