tools: refactor tools JS code

* standardize on arrow functions for callbacks
* standaradize on trailing commas for multiline arrays

PR-URL: https://github.com/nodejs/node/pull/26394


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Masashi Hirano <shisama07@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>