Support HTTP retries

[andrii-balitskyi]

Closes #96

[andrii-balitskyi]

@razor-x Are we good to merge this?

[razor-x]

@andrii-balitskyi I think it's ok to merge. I'm happy to keep Retry() as the default for now, but the other default seems ok.

Main issue is that we don't have a test, but in order to test this we would need to use seam.client anyway since Retry won't ever trigger on POST.

Let's revisit this when we have preferred method and semantic method in the blueprint.