Retry every S3 request on 5xx server errors

[mosyp]

The 5xx server errors for s3 have to be retried, however rusoto has no such feature. See discussion #510 (comment) for more details.

[viirya]

I think this can be closed now?

[houqp]

@viirya i think this issue tracks the work to make the retry more robust. Right now the current retry logic is a busy loop without sleep and exponential backoff. We might want to apply the retry more generally to other S3 api calls as well.

[ion-elgreco]

I don't believe this is relevant anymore now that we moved to the official AWS rust crates, we can open a new issue if it was still relevant