Refactor Input Interactables

[jasonbcox]

All Input_Interactable's need to be placed in new files called Input_Interactable.h/.cpp. Create a new base class called Interactable. The functionality in Input_Interactable_Button will be split into Input_Interactable and a new class called Input_Button that inherits Interactable.

The new structure will be as follows:

Input_Interactable

• bool isHit (replaces Input_Interactable_Button's getStateSimple()

Input_Button : Interactable

• Input_ButtonState getState()

Input_Keyboard : Button

Input_Mouse : Button