Create status validation for nodes

[camelya58]

Please, create status validation for nodes in create and update methods of NodeServiceRealization.
For example, when the node has created or updated it should receive automatically status MODERATED. And it would not be necessary to generate it yourself in a field while the node is being created or updated.

Currently, the NodeRequest does not have a "status" field, but it is filled with "null".

Please, also delete the field "status" from PostRequest (it has already generated automatically).

When you fix it, please describe it in already existed docs.