Introspection Needs an overhaul

[stevan]

This work was started in eaef95e

We still need to do away with the enable_for_schema and enable_for_resolvers class methods, both of them will make clones of the Schema and Resolver objects respectively and I am not a fan of that (though it is a shallow clone and since everything is immutable thats safe).

Most all other fields are now "implicit" and are handled in a way similar to the BuiltIn::Scalars in that they will return constant values (technically state variables, so the are not actually created if they are never called, but afterwards return the same values without recalculating).

• Query introspection fields (__schema, __type(name))
• Resolvers for those Query fields
• Schema Meta Model

However, a few things still need attention, like the implicit Query fields are currently added to all Object types, not just the Query instance, and we have no support for __typename.

So basically this ticket needs the following tasks completed to be closed.

• Handle __typename
• Remove the need for enable_for_schema by making what it does "implicit"
• Remove the need for enable_for_resolvers by making what it does "implicit"
• Restrict the __schema and __type(name) fields to the Query class (simply Proxy class should suffice)