New endpoint to add one element in a dataset
Refs https://redmine.teklia.com/issues/5677
We need a new endpoint available to corpus contributors, named CreateDatasetElement
which allows a user to add a single element in a dataset .
Body Parameters are:
- dataset_id
- element_id
- set_name
Checks:
- The element must be in the dataset's corpus
- the set must be in the dataset
- the dataset must be open