Support delayTransientStatuses option

[rmmeans]

DynamoDB local has a flag for "delayTransientStatuses" that tells DynamoDB local to try and behave more like the actual DynamoDB service in that some operations have detectable async latency between operations (e.g. a GSI getting updated, or new GSI's being created).

It doesn't appear they have all of the operations working correctly for this right now, but this would be a great flag to add support for so that folks can get their locally running tests more in line with the way it will actually run.

This is probably fairly easy for anyone in the community to step in and do this. Just creating an issue to be tracked.

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBLocal.html