[BEAM-13967] Add pivot_table(), a non-deferred column operation on categorical columns

[yeandy]

Adding pivot_table, a non-deferred operation. i.e. operations that produce a variable set of columns based on the intrinsic nature of the data.

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[codecov]

Codecov Report

Merging #17090 (770e6ae) into master (2aa24dc) will increase coverage by 1.95%.
The diff coverage is 92.95%.

@@            Coverage Diff             @@
##           master   #17090      +/-   ##
==========================================
+ Coverage   73.99%   75.95%   +1.95%     
==========================================
  Files         685      866     +181     
  Lines       89727   119566   +29839     
==========================================
+ Hits        66395    90814   +24419     
- Misses      22172    27592    +5420     
  Partials     1160     1160              

Flag	Coverage Δ
python	83.09% <92.95%> (-0.59%)	⬇️

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Impacted Files	Coverage Δ
sdks/python/apache_beam/dataframe/frames.py	96.45% <92.95%> (+1.18%)	⬆️

... and 380 files with indirect coverage changes

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[github-actions]

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[github-actions]

This pull request has been marked as stale due to 60 days of inactivity. It will be closed in 1 week if no further activity occurs. If you think that’s incorrect or this pull request requires a review, please simply write any comment. If closed, you can revive the PR at any time and @mention a reviewer or discuss it on the dev@beam.apache.org list. Thank you for your contributions.

[github-actions]

This pull request has been closed due to lack of activity. If you think that is incorrect, or the pull request requires review, you can revive the PR at any time.