[WIP] Use DataTransformer from ResourceBundle

New promotion-related forms were not using new DataTransformer.

Plus, they are hardly coupling PromotionBundle with AddressingBundle and TaxonomyBundle. I reduced the dependency on the parameters `sylius.model.country.class` and same for taxon. So now if you want to use PromotionBundle you just need to define these parameters. Is it enough? Shouldn't we move these 2 forms to our CoreBundle?

WIP because I'll delete the unused data transformers.