assert: provide info about actual error

In case a error is caught in `assert.doesNotThrow` or
`assert.doesNotReject` it will now also indicate what the real
error message was.

PR-URL: https://github.com/nodejs/node/pull/19884


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>