Expose WayID in Annotation Object of RouteResponse

[wangyoucao577]

We can get some contents in the Annotation object by add parameter &annotations=true when we request a route.
In the Alternatives Ranking, we're using nodes from annotation object to match traffic data. But it's not very easy to use since our traffic data indexed by wayID instead of nodes. Also, most of our other services are heavily based on wayID, so if we can add wayID in annotation object will be very helpful.

Two proposals:

1. Use an new microservice to do it between osrm-ranking and osrm-backend.
   • The new microservice will have to load wayID->nodes mapping and indexed by nodes to unpack the wayIDs.
   • Disadvantage: maybe possible to cost too much memory(not sure whether 64GB is enough for NA or not).
   • Advantage: easy to implement since don't need to change the C++ flow.
2. Support it in C++ implementation directly.
   • It may not that easy to implement, need to do some research & estimation.

I think we may go with proposal-1 at present. @CodeBear801 How's your idea?

[wangyoucao577]

Has been done by #296