Add an option to use object storage

[grantfitzsimmons]

We have a branch that we are using for our hosted users: #36

This currently replaces filesystem commands with S3 commands, eliminating the need for EFS and s3fs mounting. It is clear that self-hosted users on various platforms prefer using object storage over bind mounts to traditional networked volumes. Therefore, it makes sense for us to offer this option to all users.

We need to add a configuration variable to choose between object storage and traditional filesystem commands.