add progress className prop

[cncolder]

First of all, thanks for your contribution! :-)

Please makes sure these boxes are checked before submitting your PR, thank you!

• Make sure you follow antd's code convention.
• Run npm run lint and fix those errors before submitting in order to keep consistent code style.
• Rebase before creating a PR to keep commit history clear.
• Add some descriptions and refer relative issues for you PR.

[mention-bot]

@cncolder, thanks for your PR! By analyzing the history of the files in this pull request, we identified @warmhug, @liqi07 and @yiminghe to be potential reviewers.

[codecov]

Codecov Report

Merging #1126 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master    #1126   +/-   ##
=======================================
  Coverage   69.92%   69.92%           
=======================================
  Files         218      218           
  Lines        4090     4090           
  Branches     1215     1215           
=======================================
  Hits         2860     2860           
  Misses       1229     1229           
  Partials        1        1

Flag	Coverage Δ
#rn	72.09% <ø> (ø)	⬆️
#web	67.65% <100%> (ø)	⬆️

Impacted Files	Coverage Δ
components/progress/index.web.tsx	83.33% <100%> (ø)	⬆️

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