Update with necessary Optimistic Locking versioning data element

Description: Optimistic locking is being implemented for Kiwi. The solution is described here: https://wiki.folio.org/display/DD/Optimistic+locking+proposal

Status:
The new Optimistic Locking specific property “_version” does not exist in mod-inventory-update: https://github.com/folio-org/mod-inventory-update/blob/master/ramls/instance.json

New work
To be compliant with the implementation of Optimistic Locking, then we need to make sure that if datasets are already existing in FOLIO and an update from CBS is performed, the data element (property) “_version” can be send as well. If this new property is not present, then the update will be rejected.

Use case:
As a staff user (user A) who has an Instance/Holdings/Item in edit mode and at the same time (user B - a system initiated update) perform an update from CBS. If then the FOLIO-dataset is saved first, this edit will be overwritten by CBS update without any notification of the user A.