Show artifact name and overall progress when uploading a snap with components

[farshidtz]

What needs to get done

When uploading a snap with several components, the upload progress is shown for the snap itself, then replaced for each component. The total size of the specific artifact is shown, but not the name of what is being uploaded.

Uploading... [████████████████████                               ] 1461813248/3586724066

Why it needs to get done

It is difficult to guess the overall upload progress. It is not clear what has already been uploaded, what is currently being uploaded, and what remains.