GraphQL schema validation process

[johnymontana]

As part of (or prior to) the augment process, validate the user provided type definitions (including use of @relation and @cypher directive) to validate type defs (for example all fields of directives are included, no use of @cyper on relationship field, etc)

[michaeldgraham]

https://github.com/neo4j-graphql/neo4j-graphql-js/issues/608 ;)