Field selection / filtering

[JacobMountain]

We should add the ability to filter the fields that are selected in queries.

Possible solutions are:

• Only include only these selected fields

@GraphQLQuery(value = "field", select = {
    @GraphQLInclude("subSelection")
})
public Field getField();

• Exclude all of these fields

@GraphQLQuery(value = "field", exclude = {
    @GraphQLExclude("subSelection")
})
public Field getField();

[JacobMountain]

For sub selection of fields we could add a dot notation

@GraphQLQuery(value = "field", select = {
    @GraphQLField("subSelection.id")
})
public Field getField();