Rework lemmatizer and allow other languages

[LexABzH]

Problem

The current lemmatizer uses spacy and was originally designed to use a French model : fr-core-news-sm.
Moreover, it was meant to be used on our organization infrastructure that does not have access to the internet, but uses an artifactory where the model was preloaded.
We should get rid of theses specificities and allow the lemmatizer to use any wanted language, not only french.

Solution

TO BE DEFINED.