If the controller implements IFilter, it will be added to the filters
collection.
It's hardcoded to be 'first' as it was in MVC, but can be overridden by
implementing IOrderedFilter.
These were accidentally the same names as the action filter methods.
Oopsies. Name taken from MVC and appended Async for the async version
because that's how we roll.
Andrew Peters
Pranav K
Ryan Nowak
Louis DeJardin