While working on #352 (closed), I wanted to experiment with different options for the writeFrame microservice, including having separate urls for public and "private" routes.

Unfortunately the GargConfig and all the ancillary functions are stored into gargantext-prelude which makes changing that not very streamlined; furthermore, it seems a bit of a code smell to have those types in the prelude, as they are domain-specific data which should be easily modifiable inside the gargantext-server.

I propose we move back those data structures and the functions operating on them.

@cgenie @anoe thoughts?