GraphQL query builder functions do not generate output fields for nested queries

[KXLAA]

Faling test PR

You have a RX schema for a document in your collection with nested fields:

const mySchema = {
    version: 0,
    primaryKey: 'passportId',
    type: 'object',
    properties: {
        passportId: {
            type: 'string',
            maxLength: 100,
        },
        firstName: {
            type: 'string',
        },
        lastName: {
            type: 'string',
        },
        age: {
            type: 'integer',
            minimum: 0,
            maximum: 150,
        },
        updatedAt: {
            type: 'string',
        },
        address: {
            type: 'object',
            properties: {
                street: {
                    type: 'string',
                },
                city: {
                    type: 'string',
                },
                zip: {
                    type: 'string',
                },
            },
        },
    },
};

You want to generate GraphQL queries from this schema to support replication using the pullQueryBuilderFromRxSchema, pullStreamBuilderFromRxSchema & pushQueryBuilderFromRxSchema util functions.

Currently, the query builder functions only generate output fields for top-level keys. So given mySchema above we get the following pull query when we pass the schema to the pullQueryBuilderFromRxSchema:

query PullHuman($checkpoint: HumanInputCheckpoint, $limit: Int!) {
  pullHuman(checkpoint: $checkpoint, limit: $limit) {
    documents {
      passportId
      firstName
      lastName
      age
      updatedAt
      address 
      _deleted
    }
    checkpoint {
      passportId
      updatedAt
    }
  }
}

As you can see, the properties of address are not generated and this causes a GraphQL validation error :

GraphQLError: Field \"address\" of type \"HumanModel\" must have a selection of subfields.

ideally, the function should be able to generate output fields for nested objects as well:

query PullHuman($checkpoint: HumanInputCheckpoint, $limit: Int!) {
  pullHuman(checkpoint: $checkpoint, limit: $limit) {
    documents {
      passportId
      firstName
      lastName
      age
      updatedAt
      address {
        street
        city
        zip
      }
      _deleted
    }
    checkpoint {
      passportId
      updatedAt
    }
  }
}