onCreate for connectOrCreate should allow nested mutations

[dan-fein]

Is your feature request related to a problem? Please describe. When using connectOrCreate and the node does not exist, users should be able to connect the new node as they would with a standard create mutation.

Describe the solution you'd like You'll see here an example of what this might look like, as currently it goes against expected behavior: https://github.com/neo4j/graphql/issues/1068