Update hand-fim image

[groutr]

Summary of changes:

1. Reorganize the directory layout for easier development. Uses deploy/code directories to simplify image building. Anything in the deploy/ directory gets uploaded to codebuild and anything in code/ directory gets included in final image.
2. Remove the retry logic from dataset opening/reading. After considering this code for a bit, I don't think we actually execute it in any case short of an S3 outage.
3. Cache S3 file reads locally using fsspec. This uses the new opener interface in rasterio 1.4. Some of the files are opened twice and this should avoid redownloads by caching locally to a temporary directory.
4. Remove the s3_file import and checks file existence directly on S3 via fsspec.
5. Create a new terraform module for hand-fim image.
6. Edit code for better clarity.

Supersedes #1108

[shawncrawley]

Looks good!