Remove old unused formatter logic

ALE has three files:

- ale/formatters/usgscsm_formatter.py
- ale/formatters/isis_formatter.py
- ale/formatters/formatter.py

These are mutated copies of the same thing, and in practice only the last one, formatter.py is used when creating ISD.

The former two need to go, as they make it hard to understand how the logic works and where one should change or what code to read.