Add support for protocols

Allow injection of types based on protocols. Services can declare themselves what protocol they support and the container can then perform autowiring based on that.

```python
class SupportsFoo(Protocol):
    def foo(self) -> str:
        pass


@service(supports=SupportsFoo)
class FooBar:
    def foo(self):
        return "bar"
```

Requesting `SupportsFoo` will have `FooBar` injected.