Add pass-through support for Parker Solar Probe trajectory server.

[elwinter]

Scott Turner has create a REST-based server for PSP trajectory data at:

http://yoyodyne.jhuapl.edu:8080/swagger
http://yoyodyne.jhuapl.edu:8080/redoc

We need to quickly create a pass-through HAPI server to run on top of this REST server, essentially the same technique used in the SuperMag-specific HAPI server code.