Upgrade Unity.Abstractions to C# 8.0

[ENikS]

Description

The main goal of this upgrade is to implement new nullability checks. The new IUnityContainer will be changed to this:

public interface IUnityContainer
{
    IUnityContainer RegisterType(Type registeredType, Type? mappedToType, string? name, ITypeLifetimeManager? lifetimeManager, params InjectionMember[] injectionMembers);

    IUnityContainer RegisterInstance(Type? type, string? name, object? instance, IInstanceLifetimeManager? lifetimeManager);

    IUnityContainer RegisterFactory(Type type, string? name, Func<...> factory, IFactoryLifetimeManager? lifetimeManager, params InjectionMember[] injectionMembers);

    bool IsRegistered(Type type, string? name);

    IEnumerable<IContainerRegistration> Registrations { get; }

    object? Resolve(Type type, string? name, params ResolverOverride[] overrides);

    object BuildUp(Type type, object existing, string? name, params ResolverOverride[] overrides);

    IUnityContainer? Parent { get; }

    IUnityContainer CreateChildContainer();
}

Impact

Very minimal