Now we don't keep custom corenlp stuff in our code and it's more
portable. Also, spacy is refactored to use its own types as well as
john snow nlp.

We do that thanks to a new typeclass method for
the `MonadJobStatus` called `noJobHandle`.

This commit modifies the backend code to convert the input CSV into an
`NgramsList`, so that we can reuse the JSON API for the upload.

it also brings the CSV and JSON APIs closer in look.
Temporarily disable the `importCsvFile` function.

Also, refactored NodeStory to use Prelude database.

This commit makes possible to pass an optional `X-Garg-Error-Scheme`
header in a client request to enable the new error format.