Transfer Mode Support

[aschuma]

The application currently only supports direct connections between two VVS train stations.

The requirement now is to also support connections with transfers. This new behavior should be switchable via a feature flag, thus keeping the existing functionality untouched.

Furthermore, addresses within the VVS area should be supported as origins and destinations. If pedestrian paths are included, they should be filtered out. In the case of necessary transfers, only the first S-Bahn or tram line (referred to as "transportation_number") should be returned in the existing field. In a separate new structure, the intermediate stations and lines will be returned.

Note
The format of addresses such as "Konrad Adenauer Str 32 (Staatsgalerie)" looks like this: "streetID:1500001775:32:8111000:51:Konrad-Adenauer-Straße:Stuttgart:Konrad-Adenauer-Straße::Konrad-Adenauer-Straße:70173:ANY:DIVA_SINGLEHOUSE:3513826:755185:NBWT:VVS:0"
To find a value for an address, enter the origin and destination in the VVS timetable information (https://www3.vvs.de/), submit as search, decode the browser URL and format the deeplink parameter with a JSON formatter.