Do strict research of Wikidata entities

We have now a speel checker
If no entity found with strict comparaison, use lenient one
Merge pull request #50 from ProjetPP/stricCorrespondance

Do strict search of Wikidata entities
Force guzzle-mediawiki-client version in order to avoid Composer fail
Do conversion to DataValue just before simplification

Allows to do simplifications directly on Resources that do not map directly to Wikibase DataValues