test: include values in assertion messages

Specifically for the test-crypto-hash.js test file.

PR-URL: https://github.com/nodejs/node/pull/15996


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>