Move the GraphQL API to use Servant named routes
After !289 (merged) is merged, we will have the (REST) API all switched to use the Servant named routes, but in the interest of not changing too much in a single go, I haven't converted the GQL API to do the same, but it would be good to do so.
@cgenie if you think this could be a good learning exercise for you, feel free to pick this up, otherwise I'm very happy to.