Build Tools: Update `grunt-sass` to v3 and add `node-sass` v4.

This fixes an error in the PHP 5.2 and 5.3 Travis builds after [44219].

Props netweb.
See #45241.
Fixes #45664.

Built from https://develop.svn.wordpress.org/trunk@44233


git-svn-id: https://core.svn.wordpress.org/trunk@44063 1a063a9b-81f0-0310-95a4-ce76da25c4cd