Extended ActionFilter to also enable filtering the response side

Enables filtering the actions on both sides - request and response. Also added a base class for filter implementations (cleans up filters that only need to filter one side)
Correct me if I am wrong but these filters have to be executed in a serial fashion one after another, right? So you can make this async if you need to on top of the blocking loop? I would like to see an example where this is used to understand the rational please :)