BREAKING(cli/unstable): rename fmt of ProgressBarOption to formatter

[timreichen]

This PR replaces fmt to formatter because property abbreviations should be avoided as they are uncommon in web apis.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.15%. Comparing base (eccdeff) to head (997251a).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6707      +/-   ##
==========================================
- Coverage   94.15%   94.15%   -0.01%     
==========================================
  Files         587      587              
  Lines       42468    42468              
  Branches     6702     6702              
==========================================
- Hits        39986    39985       -1     
- Misses       2433     2434       +1     
  Partials       49       49              

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[kt3k]

I believe this aligned better with the rest of the code base. Thanks for your suggestion

LGTM