REST 404 response returned instead of 400 for POST/PUT/PATCH request types

When update operations are performed on a data fragment (list node element) the parent node xpath parameter is passed to identify the parent node of a fragment being updated.

If parent node is not found in the database the DataNodeNotFoundExeption is thrown and it causes 404 (Not Fount) response. At the same if there is no requested dataspace or anchor being found in database, the 400 (Bad Request) response is returned, indicating invalid request parameters. So the response is being inconsistent for errors having similar nature.

Actual:

404 response is returned for any request type if DataNodeNotFoundException occurs

Expected:

if parent data node is not found on POST/PUT/PATCH request method types, the 400 (Bad Request) response should be returned instead of 404. 404 is only expected for GET requests.