* Refactoring to consolidate logic
Prior to this commit, two controllers had nearly identical chunks of
logic. This refactor extracts the logic to a common and more canonical
location.
* Addressing rubocop's aggressive auto-fix
* Adding spat operator for pluck
* Renaming method for greater clarity
* Introduce domain model for campaigns
* Move main_tag method to decorator
* Add options argument to decorator method
* Change more code to use Campaign domain model
* active? -> show_in_sidebar? and fix spec
* Switch back to leading dots after merge
