* Restore DisplayAdEvents.counts_for
* Try a rollup service for DisplayAdEvent
* Schedule daily rollup worker for one month prior
* Refactor aggregator
* More testing for rollup
* Add test for rollup attribute fidelity
* DisplayAd success_rate based on counts_for
Prior to this commit, we had a couple of references to magic strings
regarding DisplayAdEvent objects. This commit seeks to consolidate that
behavior.
In a handful of cases we had javascript variables, but as these JS files
are `erb` templates, we can inject the constant as well. This reduces
repetition of knowledge.
* Add ApplicationMetalController to relevant controllers
* Add request forgery protection to metal
* Remove logger call
* Add logger keyword and skip protect_from_forgery in test
* Uncomment main_image in test
* Replace current_user.id with efficient_current_user_id in high-leverage areas
* Update name of efficient_current_user_id
* Replace user_signed_in? in pageviews
* Remove unneeded ?
