Update progress bar to show single unified progress bar

[NathanFlurry]

Motivation

• We don't have TTY when running uploads from engines. We should simplify the progress bar so it's cleaner to view without TTY.
• People don't really care about uploading individual chunks, but only the whole progress.
• If we switch from raw stdout to using update signals (for rich progress bars in-engine), we'll need a single number instead of this.

[linear[bot]]

CLI-87 Update progress bar to show single unified progress bar