[Enhancement] Data libraries point to S3 location

[MatthewRalston]

Hi everyone, I have an idea for an enhancement to both Galaxy and bioblend where data is hosted remotely on an S3 account that the Galaxy admin has access to. My understanding of the current "upload_file_from_url" method is that the data is fetched from the remote location and stored locally. You can imagine situations where data is stored in an S3 bucket for low-cost storage, but data shouldn't be retrieved until it is needed (e.g. high cost storage on EBS in comparison to S3.)