Preparations to use javascript modules and other small fixes

Related issue

This helps #1037

Context / Background

The new electron 28 changes things by providing main electron imports through JS modules. That means we'll be able to use import syntax rather than node's require(), and no longer need the esm module to use both notations. The require() notation will still be available, making it the best of both worlds for other imports that haven't migrated yet - date-holidays for example.

I'm separating a few of the changes that will need to be made for a simpler review. These changes here still work in electron 27 and will clear the field for a larger patch.

What change is being introduced by this PR?

Using the .cjs extension for files that will be using only node modules

Commit: Renaming window-aux and app-config to .cjs

Updating pre-commit script

Script was trying to format deleted files. It also had to be updated to format .cjs and .mjs files Commit: Preparing commit hook to accept mjs and cjs files, avoiding deleted files Commit: Adding all 3 js extensions to eslint target

Cleanups

Commit: Adding 'use strict' to all files Commit: Export section to have commas and be sorted, last line at end

Switching imports to `import` keyword rather than `require()`

Commit: Updating renderer electron imports Commit: Switching 'fs' import to use import Commit: Switching 'electron-store' import to use import Commit: Switching notification.js to use export Commit: Switching 'path' import to use import Commit: Switching 'electron' to use import

How will this be tested?

Testsuite works fine.

thamara / time-to-leave