This commit extends the reverse proxy for the microservices so that it
would serve a custom `/config` file which would contain the correct
baseUrl to initialise the websocket connection correctly.

Still needs to fix some hardcoded URLs. The problem with websockets is
that they use the first URL fragment to determine the documentId,
therefore we cannot proxy to `http://localhost:8009/notes/<frameId>`
because the underlying WS connection will use `noteId=notes`, which is
wrong.

This beefy commit removes the old (unnamed) Servant API.

This big commit ties the knot with the named _routes_ by providing
concrete server (i.e. handlers) implementations.

Merge branch '345-docs-tsv-export-import-check-and-maintain-consistency-between-export-and-import-formats' of https://gitlab.iscpif.fr/gargantext/haskell-gargantext into 345-docs-tsv-export-import-check-and-maintain-consistency-between-export-and-import-formats