support s3 direct to lambda replays

[rs-sathya]

I had to change the event data structure to fit a direct-to-lambda s3 event setup.

This was not a blocker because I was still able to hand-modify and run the code. However, it would be nice to support this use-case natively. The code is so close to supporting it already!

event structure to support:

{
  "Records": [
    {
      "EventSource": "aws:s3",
      "EventVersion": "2.1",
      "EventSubscriptionArn": "arn:aws:sns:us-west-2:0000:s3-sns-lambda-replay-XXXX:1234-123-12-12",
      "eventName": "ObjectCreated:Put",
      "s3": {
        "bucket": {"name": "my-bucket-name"},
        "object": {"key": "incoming/catalog/2022/05/31/23/example.gz", "size": 70601}
      }
    }, 
  ]
}