It forces programmers to think about errors we are logging and reporting
to the frontend, because they need to contain no sensitive data.

Also, some test refactoring and add servant-client to tests.

This is similar to

gargantext/purescript-gargantext#594

and

gargantext/haskell-gargantext!205/

but for JSON import.

This is a first stepping stone in avoiding bugs by having `UserId` and
`ContextId` being proper types, and not synonyms.

We also refactor things to have `AuthenticatedUser` carry the `UserId`.

Basically, Gargantext.Prelude exports all of Protolude now.

This big commit improves the jobs API in a way that now we can
completely abstract away over a JobLog.

Now the job doesn't return 'succeeded' fields when it actually fails.