Deprecate the origin_add_one() endpoint
This endpoint is not really useful since the origin_add() can be used instead.
Using a single API endpoint would also make the API a bit more consistant (most other endpoints only provide a xxx_add endpoint) ; having a single endpoint per object_type make is enough and make the whole API simpler.
Depends on !431 (closed).
Migrated from D3328 (view on Phabricator)