Provide Overload for Keys of Type Guid

[endeffects]

It would be nice if you can add the following extension methods to improve the usage.

Usage

await sessionStorage.CreateOrUpdate<SomeStateObject>(notification.Id, state => state.OnNotification(notification));

Instead of

var state = await sessionStorage.GetItem<SomeStateObject>(notification.Id) ?? new new SomeStateObject();
state.OnNotification(notification);
await sessionStorage.SetItem<SomeStateObject>(notification.Id, state);

Extensions

    public static class StorageExtensions
    {
        public static async Task<TState> CreateOrUpdate<TState>(this IStorage storage, Guid id, Action<TState> handler) where TState : class, IState
        {
            var state = await storage.GetItem<TState>($"{id}") ?? Activator.CreateInstance<TState>();

            handler(state);

            await storage.SetItem($"{id}", state);

            return state;
        }

        public static async Task<TState> Update<TState>(this IStorage storage, Guid id, Action<TState> handler) where TState : class, IState
        {
            var state = await storage.GetItem<TState>($"{id}");

            if (state == null)
            {
                throw new InvalidOperationException("State not found!");
            }

            handler(state);

            await storage.SetItem($"{id}", state);

            return state;
        }
    }