* add a CustomActionDispatchers for createProductAttribute action
* add optional options to createItem() fn
* update items object when optimisticQueryUpdate is defined
* reduce itemsCount when creating a new item
* polish TS types
* update reducer tests
* clean unused type
* clean dirty code
* add optimisticQueryUpdate test
* changelog
* minor improvement
* options could be undefined
* compute items and itemsCount based on data
* fix TS error
* changelog
Damián Suárez