New: Ability to use Original Title only in naming settings

@Taloth @kayone This will let people keep renaming on, but selectively choose which files actually get renamed and which ones use the scene name.
Yes, we can, wasn't sure if there was a reason why we fell back to String.Empty, maybe so we didn't put in a hashed filename if scene name was unknown? But in this case its worse, so I'll go with that.