This PR introduces an `upsert` parameter (along the existing `data`
param) for `createOne` and `createMany` mutations.
When upsert is set to `true`, the function will look for records with
the same id if an id was passed. If not id was passed, it will leverage
the existing duplicate check mechanism to find a duplicate. If a record
is found, then the function will perform an update instead of a create.
Unfortunately I had to remove some nice tests that existing on the args
factory. Those tests where mostly testing the duplication rule
generation logic but through a GraphQL angle. Since I moved the
duplication rule logic to a dedicated service, if I kept the tests but
mocked the service we wouldn't really be testing anything useful. The
right path would be to create new tests for this service that compare
the JSON output and not the GraphQL output but I chose not to work on
this as it's equivalent to rewriting the tests from scratch and I have
other competing priorities.
