Support AWS

[groenroos]

Create an integration for AWS to handle file upload storage, and SES/SNS for Notifications, plus any other integrations that make sense.

This should likely be its own package that can be optionally added via the CLI, so that the main package is not polluted with AWS dependencies and code that is only useful if you use AWS. It's less clear to me how a separate package can neatly hook into the bowels of, say, Storage.post to handle S3 storage.

AWS-based databases would likely be their own driver packages.