test: Remove unnecessary asserion messages in test-crypto-hash.js

This commit improves asserion messages in parallel/test-crypto-hash.js.
Instead of just simple string literal, messages are changed to also
include values used in assertion, which should improve debugging
in case of errors.

Backport-PR-URL: https://github.com/nodejs/node/pull/22380
PR-URL: https://github.com/nodejs/node/pull/18984


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>