Add automatic retries

• Adds automatic retries for all requests that can be safely retried. In the event of a network failure or internal server error, requests will be retried up to 3 times.

For POST requests, this involves adding an idempotency key to the request. These are automatically generated by default, but you can override them with the setIdempotencyKey methods.

To disable automatic retries (for example, because you have your own retry logic that you wish to use), you should use the executeWrapped method.