Extend dynamodb decorator to utilize more features of the update event source API

Hey Guys,

Is there a plan to extend dynamodb decorators to support additional flags for the update even source. I'm especially interested in the batching window, but I can imagine that some other flags could be useful.

Usual workaround with CloudFormation templating is working fine, but would be great to have it on the framework level.

The issue does not name implementation files, tests, or an entry point. Start by locating the DynamoDB decorator and comparing its generated update event source configuration with the AWS API; done means the batching window and other relevant flags can be configured through the framework and are covered by tests.

Written by the indexing model from the issue text.