This contains only data, removes some Database dependency in imports.

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.

FlowCmdM -> DBCmd or HasNodeStory is usually enough

Remove joins, use optionalRestrict instead.

Also, remove cabal.project because stack.yaml and package.yaml cover
dependencies already.