[ngrams] NgramsTerm normalization

It is not enough to normalize terms on the backend, because the frontend
isn't fully aware of this (there isn't a "corrected" patch being sent,
after the term is committed). Therefore we perform some normalization
here (stripping spaces). However the `normNgram` function is used both
for sending terms and highlighting them later. Too much normalization
will lead to incorrect highlights.

src/Gargantext/Components/NgramsTable/Core.purs

@@ -179,8 +179,11 @@ normNgramInternal CTabSources    = identity
 normNgramInternal CTabInstitutes = identity
 normNgramInternal CTabTerms      = S.toLower <<< R.replace wordBoundaryReg " "
 
+normNgramWithTrim :: CTabNgramType -> String -> String
+normNgramWithTrim nt = DSC.trim <<< normNgramInternal nt
+
 normNgram :: CTabNgramType -> String -> NgramsTerm
-normNgram tabType = NormNgramsTerm <<< normNgramInternal tabType
+normNgram tabType = NormNgramsTerm <<< normNgramWithTrim tabType
 
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 newtype NgramsElement = NgramsElement