Add consumer-based RfC Visibility settings

This setting will be useful to increase data protection, where users might not be allowed to see RfCs from other contexts.

app/controllers/consumers_controller.rb

@@ -23,7 +23,7 @@ class ConsumersController < ApplicationController
   end
 
   def consumer_params
-    params[:consumer].permit(:name, :oauth_key, :oauth_secret) if params[:consumer].present?
+    params[:consumer].permit(:name, :oauth_key, :oauth_secret, :rfc_visibility) if params[:consumer].present?
   end
   private :consumer_params