Implement automatic retries in aws-elixir

[onno-vos-dev]

Description

In aws-erlang myself and a colleague implemented automatic retries as part of aws-beam/aws-erlang#57. This may be a feature of interest for aws-elixir as well but seeing as I'm not super-duper-familiar with this codebase (nor Elixir for that matter) I'm opening an issue instead in case anybody else feels like picking this up :-) It could be a nice beginners task.

Criteria

• Implement retry mechanism in aws-elixir using exponential backoff with jitter.
• Ensure backwards compatibility, if no retry opts are passed, no retry mechanism should be applied.
• Don't make the same mistake we made in onno-vos-dev/aws-erlang@5f4f9d9 and ensure all error cases are correctly handled. 😅

Example implementation: onno-vos-dev/aws-erlang@7078533