stdcm: refacto: have core return a train schedule *input* instead of the output directly

Currently, the core api for stdcm returns this:

class STDCMSuccess(
    var simulation: SimulationResponse,
    var path: PathfindingBlockResponse,
    @Json(name = "departure_time") var departureTime: ZonedDateTime
) : STDCMResponseV2

We directly return the simulation response in a format that's identical to the one returned by the simulation endpoint.

What we could do instead would be to return a train schedule, as in, the input for a simulation call. Editoast would then be in charge of sending a new request to core to get the actual results.

This would let us cache and re-use lots of components and generally makes more sense.

This refactoring is briefly mentioned in https://github.com/osrd-project/osrd-confidential/issues/331, it came up in a workshop when discussion this issue.

OpenRailAssociation / osrd

stdcm: refacto: have core return a train schedule input instead of the output directly #7653

OpenRailAssociation / osrd

stdcm: refacto: have core return a train schedule *input* instead of the output directly #7653

stdcm: refacto: have core return a train schedule input instead of the output directly #7653