[EtherCalc] add Gargantext Utils for EtherCalc

src/Gargantext/Utils/EtherCalc.purs

+module Gargantext.Utils.EtherCalc where
+
+import Affjax (Error, Response, defaultRequest, request)
+import Affjax.ResponseFormat as ResponseFormat
+import Data.Either (Either(..))
+import Data.HTTP.Method (Method(GET))
+import Effect.Aff (Aff)
+import Gargantext.Prelude
+
+type Base = String
+type NodeId = String
+
+downloadCSV :: Base -> NodeId -> Aff (Either Error (Response String))
+downloadCSV base nodeId = do
+  let req = defaultRequest
+            { url = base <> "/" <> nodeId <> ".csv"
+            , responseFormat = ResponseFormat.string
+            , method = Left GET }
+  request req
+