These types are the same, except for Database.Empty

I managed to have backwards compatibility with the frontend format,
hence the frontend doesn't need any changes.

This simplifies the WithQuery structure even more

Also, add WithQuery pubmed test (with api_key)

There is now only a 'datafield' field, no need for duplicated
'database'.

Related to #441

[graphql] fix droping field prefixes

See merge request !379

It wasn't used anyways.

I want to understand ngrams algorithms better.

Upgrade 'haskell-bee' version, also bump up versions of some packages

See merge request !377

Resolve "Fix test build warnings"

See merge request !376

Also, add -Werror to tests so that no warnings in tests are reported anymore.

Switch to OpenAPI3 from Swagger2, to use proper Bearer token

Closes #427

See merge request !369

This commit adds three major tags to the swagger UI:

* Gargantext (like before): this spells out all the endpoints;
* Private operations: lists private backend ops;
* Public  operations: lists public backend ops.

More can be added, but the machinery used here should serve as a
blueprint.