Harmonize comfort types

[SharglutDev]

Description and goal

With Trainschedule v2 model, we now use the type Comfort to define the comfort of a train in stdcmV2 and trainscheduleV2 (TrainScheduleBase type) endpoints.

The old model was using type RollingStockComfortType. Most of it will be removed when dropping v1 model.

But in rollingstock endpoints, we keep using this old type for effort curves and it should be harmonized with the new model.

Acceptance criteria

• Type RollingStockComfortType is removed from the code base
• All references of 'AC' instead of 'AIR_CONDITIONING'should be removed (including trads)
• Type Comfort is now used for all rolling stock endpoints
• Type TrainScheduleBase use Comfort for its comfort property