ActiveStorge blobs can currently only be saved in a local storage (on disk). We want to support S3-comparable storage to support containerization. Steps: - [ ] Add optional configuration to use S3 as storage - [ ] Mirror local blobs to S3 storage - [ ] Add remaining local data to S3 - [ ] Use S3 as default provider - [ ] Remove mirroring and only use S3 - [ ] Remove local data