Unauthenticated GraphQL access by prepending __schema to private operations

Summary

The security researcher (@pwnie) identified a vulnerability which allowed bypassing authentication for queries in the GraphQL schema of the Enjin Platform. This security researcher went through an then located exactly where the vulnerability was introduced within the platform-core repository so that a rapid fix could be introduced. The code identified by @pwnie was confirmed to be correct and the fix addressed the logic in question.

Since authentication isn't strictly necessary for most of the queries, it was possible to perform a large number of different queries without any errors occurring using this bypass. However, for those queries that did perform authentication checks, it would later trigger a server error as the authentication logic later failed when retrieving the user's information.