Implement Instant globals

https://wikia-inc.atlassian.net/browse/PLATFORM-236

This extension emits WikiFactory variables as JS globals. Variables are exposed via ResourceLoader module (loaded at the top of the page along with abtesting config) with a short CDN caching time, allowing us to make critical config changes with no need to wait 24h for CDN page cache to invalidate.

* ``InstantGlobalsModule::$variables`` contains the list of WF variables to be emitted by the module
* variables values are taken from Community Wiki
* caching time on both server and client-side is 300 sec
* RL module is only loaded in Oasis

@bognix / @gabrys / @prein / @michalroszka / @federico-lox 

**Do not merge** Waiting for QA from Ads team.