Inline Fragments for interfaces (attempt #1) - #133

So this isn't ideal but it was the first method I got to work.

Essentially it allows this

query {
    animals {
        name
        ... on Cat {
            lives 
        }
        ...on Dog {
            hasBone 
        }
    }
}

however it will include all the properties on all types, but as the default value if it doesn't exist on that type. (eg Dogs will have 0 lives and Cats will have !hasBone).

I'm also trying another method which involves updating MakeSelectWithDynamicType to include Expression.Switch that check the types, but as always Expression Trees are quite hard to work with.