Add PytorchBatchConverter

[yeandy]

Adding PytorchBatchConverter as discussed in https://github.com/apache/beam/issues/21440 as an initial step to integrate Batched DoFns into RunInference.

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[yeandy]

R: @TheNeuralBit

[github-actions[bot]]

Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control

[codecov[bot]]

Codecov Report

Merging #23296 (9d537b8) into master (0d937d4) will decrease coverage by 0.27%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master   #23296      +/-   ##
==========================================
- Coverage   73.58%   73.31%   -0.28%     
==========================================
  Files         716      720       +4     
  Lines       95301    95766     +465     
==========================================
+ Hits        70127    70208      +81     
- Misses      23878    24262     +384     
  Partials     1296     1296              

Flag	Coverage Δ
python	82.94% <0.00%> (-0.46%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...pache_beam/typehints/pytorch_type_compatibility.py	0.00% <0.00%> (ø)
sdks/python/apache_beam/io/gcp/bigquery_tools.py	73.30% <0.00%> (-12.43%)	:arrow_down:
...s/interactive/dataproc/dataproc_cluster_manager.py	71.72% <0.00%> (-5.70%)	:arrow_down:
.../python/apache_beam/testing/test_stream_service.py	88.09% <0.00%> (-4.77%)	:arrow_down:
sdks/python/apache_beam/io/gcp/bigquery.py	71.31% <0.00%> (-2.94%)	:arrow_down:
sdks/python/apache_beam/internal/gcp/json_value.py	85.50% <0.00%> (-2.90%)	:arrow_down:
...on/apache_beam/runners/dataflow/dataflow_runner.py	80.88% <0.00%> (-2.12%)	:arrow_down:
sdks/python/apache_beam/typehints/schemas.py	91.89% <0.00%> (-1.96%)	:arrow_down:
sdks/python/apache_beam/runners/runner.py	72.39% <0.00%> (-1.85%)	:arrow_down:
...che_beam/runners/interactive/interactive_runner.py	90.50% <0.00%> (-0.89%)	:arrow_down:
... and 48 more

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[yeandy]

PTAL @TheNeuralBit

[TheNeuralBit]

It looks like codecov is unhappy since this file looks untested. Presumably because we don't have pytorch installed in the run generating coverage data. I confirmed this test is exercised on Jenkins:

[yeandy]

Thanks for the small fix and confirmation!