test: check TTY mode reset on exit

Before PR 20592, closing all handles associated with the main
event loop would also mean that `uv_tty_reset_mode()`
can’t function properly because the corresponding FDs have
already been closed.

Add regression tests for this condition.

Refs: https://github.com/nodejs/node/issues/21020
Refs: https://github.com/nodejs/node/pull/20592

PR-URL: https://github.com/nodejs/node/pull/21027


Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: James M Snell <jasnell@gmail.com>