S3 connector for presigned URLs

[#1]

Description - The AWS S3 connector provides a way to generate presigned URLs for both GET and PUT operations to a bucket.

Why is this feature important to you - In WF/Fusion implementations (a common stack), if the customer is an AWS shop, a lambda function must be deployed just to generate presigned URLs. I _believe_ you could re-create the presigned URL algorithm in Fusion using the SHA256 HMAC function, but it's more intuitive to just use AWS's `boto3` and write a ~15 line script for generating presigned URLs and returning GET and PUT urls for a given object key. And it would be even _more_ intuitive to just have the option in Fusion.

How would you like the feature to work - Either create a separate S3 module for "Presigned URLs", or, enable a toggle on the Download a file/Upload a file modules to return presigned URLs, allowing the user to input desired expiry and other inputs to the presigned URL generation process.

Current Behaviour - No presigned URL generation for AWS S3 whatsoever.

[#2]

For sure... this will be critical! It should be as simple as a checkbox, "created predesigned url" with an expiration text field.