Feature/inbox s3 bucket

[viklund]

Describe the pull request:

• [ ] Bug fix
• [ ] Functional change
• [x] New feature
• [ ] Code cleanup
• [ ] Build system change
• [ ] Documentation change
• [ ] Language translation

Pull request long description:

We are running with the inbox directly on top of S3, for that we need to configure the ingest service somewhat differently. We have the same bucket for all users but they are chrooted into different subfolders of that bucket, this update to ingest.py and the storage backend makes it possible to use the S3 backend in this way.

Changes made:

• Separated inbox and archive setup into their own functions
• Enabled ingest to work with prefixed S3-based inbox

[silverdaz]

Closing it as it seems stale. Re-open if needed.