title: Query by relationship for GraphQL?
body: <p>How would you use graphQL to query by a "relational" entity value?
  For instance, lets say we have a bunch of person-objects. Each "person" then has a relation to an interest/hobby which then has a property called "name".
  Now lets say that we want to query for the name of each person with a specific interest, how would such a query be "conducted" using GraphQL?
  Using OData it would be something like Persons?$select=name&amp;$expand(Interests($filter=name eq 'Surfing')).. what would be the equivalent for GraphQL?</p>