cli: revert format() related changes

[xavfernandez]

Since the progress bar API is % related, it seems simpler to stick with
it.
Fix #6973 (comment) after #7826

[xavfernandez]

An alternative would be to provide an updated update method to BaseDownloadProgressBar.

[jaraco]

I apologize for not getting this right. I guess it wasn't covered by the tests. I'd be happy to provide a .format fix instead (and test it or consider writing tests) if there's interest in having the pip codebase be pure w.r.t. % formatters.

[atugushev]

@xavfernandez thanks for the fix! Works fine now.

[pradyunsg]

I apologize for not getting this right.

No worries -- we're all human!

I'd be happy to provide a .format fix instead (and test it or consider writing tests) if there's interest in having the pip codebase be pure w.r.t. % formatters.

This, would be awesome!

[xavfernandez]

I apologize for not getting this right. I guess it wasn't covered by the tests. I'd be happy to provide a .format fix instead (and test it or consider writing tests) if there's interest in having the pip codebase be pure w.r.t. % formatters.

@jaraco no need to apologize, we now know we are lacking tests on this part and an other fix with tests would be most welcome 👍

[xavfernandez]

@atugushev you're welcome ! Thanks for eagerly testing the master branch :)

[jaraco]

This, would be awesome!

I see now that the vendored package is built based on % formatters; what you meant by:

Since the progress bar API is % related, it seems simpler to stick with it.

I agree.