Revisit IJsonOutputFormatter

[danroth27]

IJsonOutputFormatter is currently just used as a marker interface to indicate that a formatter outputs JSON. We should revisit this approach and see if we can come up with something cleaner and more general.

[danroth27]

We decided to remove the dependency on formatting in JsonResult and JsonViewComponentResult and instead just use JSON.NET directly. Remove IJsonOutputFormatter as part of this work.

[ajaybhargavb]

Part 1 - f206cf6