Move all Vector JavaScript to ResourceLoader `packageFiles`[0] which are
much more compatible with modern development practices:
- The entrypoint is the first `packageFiles` entry (unless specified
otherwise). All other JavaScript must be explicitly executed.
- Remove a level of indentation due to IIFEs from every JavaScript file.
Regretfully, ESLint does not support modules except in ES6+ so the
otherwise useful `no-implicit-globals` rule must be disable. The
change comes with a comment so we always remember.
- IDEs and other tooling understand Node.js-like `module.exports` /
`require()`.
This change seemed the most sensible way to start developing new
JavaScript in Vector needed by the collapsible sidebar.
[0]: https://www.mediawiki.org/wiki/ResourceLoader/Package_modules
Change-Id: I287e604d5b1055aa97b5f987c24872755757ea1a