move webpack publicPath setup earlier in the bootstrap processes to avoid ES module execution order issues

Start of the new navigation by redesigning just the top navigation menu.
This is only shown when a cookie is set.

Part of #32794

Signed-off-by: NRémy Coutable <remy@rymai.me>

Add test.js and test.css to disable animations during testing and include these in _head when testing

Add test.js and test.css to disable animations during testing and include these in _head when testing

Add the following line to GDK Procfile to play with it:

    webpack: exec support/exec-cd gitlab npm run dev-server

With events no longer being cached this is no longer needed.

This makes larger libraries more cacheable and will allow us to use SRI with the dynamically included libraries.

This prevents compromised or malicious CDNs from modifying assets. The hash provided by Rails is compared to the hash of the asset the browser has downloaded. The browser will refuse to execute/parse the assets if the hashes don't match. SRI is currently implemented in Firefox, Chrome, and Opera.

More information is available in #18230 and on MDN: https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity

This doesn't apply to the dynamically-generated per-page JavaScript due to a bug in sprockets-rails (https://github.com/rails/sprockets-rails/issues/359).

- Turbolinks caches the `head`, so `gon` updates don't show up unless
  the user navigates to page directly (by URL) or performs a refresh.
- The solution is to render `gon` in the body instead.
- Also update the syntax to the new Rails 4 (according to the gon
  README) syntax.

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

See http://apple.co/1SCRzrw

Closes #13540

[ci skip]