Retrieve similar entity instead of creating a new one
Refs https://gitlab.com/teklia/requests/-/issues/797
Depends #1410 (closed)
The CreateEntity
endpoint should have a boolean option use_existing
(defaults to False), that add an extra step to the endpoint.
When enabled, the endpoint will first look if an entity with the same name and type already exists in the corpus. If found, the existing entity is given as result, without creating a new one.