[FEATURE REQUEST] Add multipoint offer requests

[matt-wirtz]

Is your feature request related to a problem? Please describe.

When requesting offers in V1.5 one can specify one start point from and one destination point to. Especially for intermodal trips where the user switches the mode of travelling during his trip, there are quite often several options for where to change modes. For each of the option one has to request an offer which means a http request that needs to be send and processed.

Urgency

It would make things more efficient so it's not crucial.

Describe the solution you'd like

If it would be possible to make multipoint offer request one could request offers from e.g. one start point to multiple destinations in one http call. That would mean that the to and from will become arrays rather then single attributes. In the request for each from and to pair an offer, if available, is generated.

[edwinvandenbelt]

I see the advantage (less internet traffic), but we should consider how often this is needed and how much burden we'll put on implementations. Personally, I tend to say that this will be used only occasionally, and it lead to questions and frustrated software developers. "What if we only can provide services on one of the requested trajectories? Should we return only this one or none?".