[PFF] Issues with tracking data deserializer.

It looks like we have multipe issues in the PFF deserializer:
- [ ] `starting` is set to `None` for all players. Maybe we need a helper function to determine which players are starters. 
- [ ] `starting_position` is set for every player, not only starting players. Not sure if this is expected behavior.
- [ ] It seems setting `STATIC_HOME_AWAY` does not accurately set 3rd and 4th periods.