* Enable updating additional account information from user preferences via rest api
Resolves#6553
* Pacify rubocop
* Decoerce incoming settings in UserSettingsDecorator
* Create user preferences hash directly from incoming credentials instead of going through ActionController::Parameters
* Clean up user preferences update
* Use ActiveModel::Type::Boolean instead of manually checking stringified number equivalence
* Move ApiController to Api/BaseController
* API controllers inherit from Api::BaseController
* Add coverage for various error cases in api/base controller