Copy one location e.g. dir to other location e.g.s3

[muhamadazmy]

rfs copy mode where we can just use one .fl to create a new .fl but also move the blobs from one store to another.

So we can simply create a .fl file with dir store (which store the blobs locally), then we can run a rfs clone that basically clones the entire flists, but also upload all blobs from the source store to destination store

This should work from any source store type to any destination store type.

[muhamadazmy]

Make sure that downloads/uploads are done in parallel for performance