Compression for S3 Upload / Download

[dylanbhughes]

Current behavior

Inspired by: https://prefect-community.slack.com/archives/CL09KU1K7/p1599160102266700

The S3 tasks in the task library currently don't compress/uncompress data for you. It would be a lot cooler if they did.

Proposed behavior

Add a compression argument to these tasks that could support different methods. Maybe start with gzip?

Example

Sometimes we want to compress info before uploading to S3 to save on upload/download time.

[cicdw]

Closed by #3297