Update KPVs: ILS deviation altitude ranges

New altitude ranges chosen to be 1500-1000, 1000-500, 500-200.
Tidied code for other ILS KPVs.
Updated KPV Tests: ILS deviation altitude ranges.

Also refactored to remove repetition and stubbed out some more tests.
Updated KPVs: TAWS GS: Match ILS altitude ranges

Matching the altitude ranges used by the ILS deviation KPVs.

Altitude ranges are: 1500-1000, 1000-500, 500-200.
Remove trailing whitespace.
Properly indent docstrings in test helper classes.
Remove a whole load of duplicate KPV tests!
Tidied up other TAWS KPVs.
Fix KPVs: TOGA should be uppercase in name.

Also tidied code for TOGA KPVs.
Fix KPV: 'Altitude At Go Around Gear Up Selection'

- Simplify the name and document the class.
- Value of pit_index was incorrect - use min_value to preserve offset.
- Tidied the code for the KPV - reduced indentation.
Merge branch 'master' of github.com:FlightDataServices/FlightDataAnalyzer