Merge trip index for real-time and on-board depart. #1118

- TableTripPattern store a list of PatternHop instead of a list of Stops.
- Dynamically compute the list of Stops through PatternHop.
- Change TransitIndexService map of Trip -> List<PatternHop> to Trip -> TableTripPattern.
- Use TransitIndexService in real-time updater.

Be careful, as in its current state this *require* the building of a transit index for real-time update. Not implemented (yet): compute on demand the index on loading.