Add a progress bar to CLI commands

[jessestorbeck]

Implementing a meaningful progress bar would be a nice user-friendly addition to the CLI. However, the options which I've looked into seem involved. For instance, cli-progress would require us to manually/explicitly increment the progress bar in the code, which could be simple for a command which simply loops through the same process many times, but could be difficult in the case of Pushkin. We could easily enough add a bar that went 0% --> 50% --> 100%, but I don't know if that's much better than nothing at all. Something like listr2 could also be nice, but it seems like it would require restructuring the code a fair bit.

[hunterschep]

@jessestorbeck is this still something we would be looking to implement? I noticed there is now a progress bar when running certain commands like prep.

[jessestorbeck]

@hunterschep -- There haven't been any changes that implement a progress bar. I think there's a dependency which logs a bunch of little progress bars (I think during start) in verbose mode, but nothing has changed re: this issue. It should stay open as a reminder that implementing a progress bar is an eventual goal for the CLI.