Next steps to expand DI functionality just in case

## Open-generics support

Add registrations dictionary of
```cs
Key: Type
Value: Func>>
```
where Type in a Value is the closed-generic known upon resolution

## Register Type

Construct a manual expression.

## RegisterDelegate and RegisterInstance

Additional dictionaries with instances and delegates.

**We can establish a determined order of resolution** across the registration dictionaries we have.

## Singletons and Scopes

- Add scope hierarchy ending with singleton.
- Add OpenScope to IResolverContext
- Single dictionary of `Type -> object` inside