Allow users to set preferred locale in settings and provide basic date and time localization support (#1226)

* Add basic date and time localization

* Normalize translations

* Localize transaction dates

* Removed unsupported Rails locales

app/controllers/settings/preferences_controller.rb

@@ -21,6 +21,6 @@ class Settings::PreferencesController < SettingsController
   private
 
     def preference_params
-      params.require(:user).permit(family_attributes: [ :id, :currency ])
+      params.require(:user).permit(family_attributes: [ :id, :currency, :locale ])
     end
 end