[ngrams] specialCharNormalize to properly highlight accents

But this will never be the same with what the backend is doing.

src/Gargantext/Core/NgramsTable/Functions.purs

@@ -47,6 +47,7 @@ import Gargantext.Types (AsyncTask, AsyncTaskType(..), AsyncTaskWithType(..), CT
 import Gargantext.Utils.Either (eitherMap)
 --import Gargantext.Utils.KarpRabin (indicesOfAny)
 import Gargantext.Utils.Reactix as R2
+import Gargantext.Utils.String as GS
 import Partial (crashWith)
 import Partial.Unsafe (unsafePartial)
 import Reactix as R
@@ -82,7 +83,9 @@ normNgramInternal :: CTabNgramType -> String -> String
 normNgramInternal CTabAuthors    = identity
 normNgramInternal CTabSources    = identity
 normNgramInternal CTabInstitutes = identity
-normNgramInternal CTabTerms      = S.toLower <<< R.replace wordBoundaryReg " "
+normNgramInternal CTabTerms      = GS.specialCharNormalize
+                               <<< S.toLower
+                               <<< R.replace wordBoundaryReg " "
 
 normNgramWithTrim :: CTabNgramType -> String -> String
 normNgramWithTrim nt = DSC.trim <<< normNgramInternal nt

src/Gargantext/Utils/String.js

 export function _btoa(s) {
-    return btoa(unescape(encodeURIComponent(s)));
+  return btoa(unescape(encodeURIComponent(s)));
+}
+
+export function _specialCharNormalize(s) {
+  return s.normalize('NFD').replace(/[\u0300-\u036f]/g, '');
 }

src/Gargantext/Utils/String.purs

@@ -7,9 +7,14 @@ import Data.Int as Int
 import Data.Number.Format as DNF
 
 foreign import _btoa :: Fn1 String String
+foreign import _specialCharNormalize :: Fn1 String String
 
 btoa :: String -> String
 btoa = runFn1 _btoa
 
 intToString :: Int -> String
 intToString = DNF.toString <<< Int.toNumber
+
+-- | https://ricardometring.com/javascript-replace-special-characters
+specialCharNormalize :: String -> String
+specialCharNormalize = runFn1 _specialCharNormalize