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

This reverts commit f4284b4e.

This reverts commit efbe327f, reversing
changes made to 6d9bcd07.

We have contexts.hash_id which is enough (computed by postgres as a
trigger).

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.

NOTE This doesn't compile yet.

This doesn't compile yet.

This is only the endpoint, it does nothing yet.