Question: How do you recommend enforcing authorization?

Hello,

I'd like to systematically enforce authorization for nodes and individual fields within the nodes.

Conceptually something like this might work:

```python
class MyNode(AuthZSQLAlchemyObjectType):
class Meta:
model = MyModel
authorize_node_function = node_authorizer
field_auth = dict(
"name": all_authorizer,
"private_things": self_only_authorizer,
)
```

`node_authorizer(model_instance)` would get called whenever a new Node of that type is created. Only fields in the field_auth dict would be exposed in node, and then the associated function would be called like `resolve_authorizer(model_instance, field_name)`

Any opinions on the best way to achieve this?