* Disable footstep sounds for ghosts
Adds a check before playing footstep sounds to check if the mover is a ghost. Doesn't play footstep sounds if they are a ghost.
* Add FootstepSoundComponent
Adds FootstepSoundComponent. If a mob has this component, it will make footstep sounds. Otherwise they will not. As of this commit humans have this component and ghosts do not.
