Use elevator status information for routing

[jessicaKoehnke]

Is your feature request related to a problem? Please describe.
Wheelchair accesible routing for trains heavily relies on elevators. When an elevator on route is out of order, it is very frustrating for passengers who rely on wheelchair accesibility. If elevators that are currently not working as expected are disregarded from the routing algorithm, the overall quality of wheelchair accessible routing will be greatly improved.

Goal / high level use-case
Improving wheelchair accessible routing

Describe the solution you'd like
It should be possible to send realtime updates for elevators (eg: elevator x is working/not working). As a dataformat Siri FM can be used, as described here: https://public.3.basecamp.com/p/KQmHscqMZqdvUUZojfsMi5PW
The affected elevators are then deleted from or added to the graph, similarly on how vehicle parkings are updated in the VehicleParkingUpdater. In the case that not all necessary elevator information for a new elevator edge are contained in the elevator is working again update, the edges might have to be replaced by a modified edge instead. As a result elevators that are currently out of order are not considered by the routing algorithm.

Describe alternatives you've considered
Alternativley the street graph would have to be rebuild every time a status changes. The OSM data would have to be modified, probably by a tool outside of OTP. It would take relatively long for every status change to take effect and this would not scale for a larger number of elevators.

Additional context

• In our case we get the static elevator data from OSM, the elevator/facility id used in Siri will have to match the OSM data. This is a data problem that we are willing to take care of.
• We get several elevator status changes an hour (distributed over ~300 elevators), rebuilding the graph every time is unfotunately not feasible.
• We do not want to implement elevator schedules, just ad hoc elevator working/not working messages