Add visual feedback when pulling and pushing

[petewall]

Pulling and pushing can take a long time. I'd be nice to see text-based progress bar for these steps.

[petewall]

The write command (for pushing) allows for adding an updates channel. Here's an example: https://github.com/google/go-containerregistry/blob/7e30746dde2f5a19b609f885dfef4e7b1d1503ad/pkg/v1/tarball/progress_test.go

Note: this does not work for pulls, but maybe that's OK? I think the push is more important than the pull.

[josvazg]

This might be difficult now that we moved to a simple log compatible logger. The default Golang logger outs 1 line per call.

How do we want to output that progress? Maybe?

1%
3%
...
100%

If we want something more interactive, then we need to break up the library interface into more fine-grained calls so that we can control all the output of the process without the library involvement.

That in turn might allow us to remove the logger as input on the higher level Coarse grained interface. But I am not sure how much of a priority that is, of if we want to expose such a fine grained interface to end consumers as well as the higher level interface.