Start and archive streams using aggregate handlers

[rigtigeEmil]

Is your feature request related to a problem? Please describe.
Starting a stream is doable outside of an aggregate handler like this. It works, but it's a bit verbose, and not very easy on the eyes, so perhaps just a fancy wrapper method could do the trick

public static class MyCommandHandler
{
    public static (MyEvent, IStartStream) Handle(MyCommand command)
    {
        var @event = new MyEvent();

        return (@event, MartenOps.StartStream<MyAggregate>(@event.Id, @event));
    }
}

There does not seem to be a similar way of archiving a stream. A solution like above would suffice, even if I'm sure the Wolverine team has ideas for something even nicer. Might be;

public static class MyCommandHandler
{
    public static (MyEvent, IArchiveStream) Handle(MyCommand command)
    {
        var @event = new MyEvent();

        return (@event, MartenOps.Archive<MyAggregate>(@event.Id, @event));
    }
}

Describe the solution you'd like
In a perfect world, both these scenarios would be tied into the aggregate workflow. Starting an event could(?) be:

[AggregateHandler]
public static class MyCommandHandler
{
    public static MyEvent Handle(MyCommand command)
    {
        // if information can be inferred from the event type that something archives/starts a stream?
        return new MyEvent();
    }
}

If more information is required, maybe another attribute or something that easily wraps the handler and indicates that it's an event starting a new stream:

[AggregateHandler]
public static class MyCommandHandler
{
    [StartStream]
    public static MyEvent Handle(MyCommand command)
    {
        return new MyEvent();
    }
}

A very similar API would be very nice for archiving a stream:

[AggregateHandler]
public static class MyCommandHandler
{
    [ArchiveStream]
    public static MyEvent Handle(MyCommand command)
    {
        return new MyEvent();
    }
}