|SOURCE|
[Common::GameplayEvents::GameplayInputListener]
* In HandleEvent, DEBUG_CAMERA_MOVE_FORWARD and DEBUG_CAMERA_MOVE_BACKWARD have
  their velocities reversed, as the direction in ZED's FreeCamera is negated
|SOURCE|
[Common::GameplayEvents]
* Added DEBUG_CAMERA_TOGGLE to enable and disable the camera
* GameplayInputListener
  * HandleEvent will only manipulate the debug camera if it is active
  * Key F1 will toggle the active staus of the debug camera
[Common::GameplayGameState]
* ToggleDebugCamera sets the debug camera's active status to either ZED_TRUE or
  ZED_FALSE
* DebugCameraActive returns whether or not the debug camera is able to be
  controlled and is the current camera to render from