WIP: get/save user decision callback

I started this and wanted to make sure this was something that made sense before finishing it and making it look pretty. Basically the idea would be to relieve the `authorize` view from making api calls and just focusing on rendering a view and having a couple of extra callbacks that would allow consumers to get/save the authorization decisions of the users. In my mind it makes sense. Let me know what you think, @timshadel.