2.2.0

Bug fixes

Forbid reference data removal when used by a product
Rework export to deal with simple reference data, reference data with translations, reference data linked to other reference data

Remove Normalizer\ReferableNormalizer, pim_custom_entity.normalizer.referable.class parameter and pim_custom_entity.normalizer.referable service
Remove Checker\ProductLinkChecker, Checker\ProductLinkCheckerInterface, pim_custom_entity.checker.product_link.class parameter and pim_custom_entity.checker.product_link service
Remove Remover\CustomEntityRemover
Move Repository\AttributeRepository to Entity\Repository\AttributeRepository
Change __constructor of Connector/Processor/Normalization/ReferenceDataProcessor to remove PropertyAccessorInterface parameter