LPS-43116 this logic only makes sense when the name is empty
LPS-43116 make sure the default vocabulary doesn't already exist (even if the current user can not view it)
LPS-43116 Revert previous commit. We cannot make a parameter dependant on the value from other (name <-> addDefaultVocabulary). Even when working in this case, it can cause confusion from users using the API and change the previous behaviour.