PIM-3371 : validate a product through validator
PIM-3371 : add a command to validate a product
PIM-3371 : add support for class constraint in metadata factory, add not
supported exceptions
PIM-3371 : update metric validator to validate product value, clean unique value validator
PIM-3371 : fix validator to avoid validation when metric data is null
PIM-3371 : re-work unique value validator to use it without form
PIM-3371 : re-work product value metadata factory
PIM-3371 : re-work specs for delegating metadata factory
PIM-3371 : fix unique value validator when apply on number, datetime
Merge pull request #1819 from akeneo/PIM-3371

PIM-3371 Validate a product and its values through a validator