Convert scripts from CommonJS to modern ESM format

[afarber]

Issue

Fix the #7226 by

• Rename *.cjs scripts to *.js and convert them to ESM
• Convert var to let/const
• Add 1 line comments to each script

Tasklist

• CHANGELOG.md entry (How to write a changelog entry)
• update relevant Wiki pages
• add tests (see testing documentation)
• review
• adjust for comments

Requirements / Relations

Link any requirements here. Other pull requests this PR is based on?

[afarber]

Hi @DennisOSRM you asked me to create node.js related issues to follow up and clean up.

So I have created 4 issues last week and this PR fixes the first of them:

• Complete CommonJS to ESM migration for remaining scripts #7226
• Replace custom flatbuffers.cjs with npm package #7227
• Add husky pre-commit hooks for linting and formatting #7228
• Standardize linting configuration across the project #7229

Please review

[afarber]

Hi @DennisOSRM please consider merging to master, then I can implement the other 3 PRs (they are based on this one)