Add a unique contraint for all node IDs

[Tirokk]

[roschaefer]

@Tirokk cool, but could you provide some tests?

[appinteractive]

Which framework @appinteractive and where?

You are right, it’s just the UUID creation in neo4j-graphql-js:

If an ID typed field is specified in the type defintion, but not provided when the create mutation is executed then a random UUID will be generated and stored in the database.