lib: remove queue implementation from JSStreamWrap

The streams implementation generally ensures that only one write()
call is active at a time. `JSStreamWrap` instances still kept
queue of write reqeuests in spite of that; refactor it away.

Also, fold `isAlive()` into a constant function on the native side.

PR-URL: https://github.com/nodejs/node/pull/17918


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>