Once the type of interface is decided, the next step is to model which endpoints will be part of the official API. The current proto file can be used as reference, but we don't need to support everything that is in there.

https://github.com/jaegertracing/jaeger-idl/blob/master/proto/api_v2/query.proto

Additionally, we should consider adding an endpoint for bulk retrieval of data, useful for consumers doing data analysis. TRACING-1902 can be used as reference for this.