[DOC-11506] Add collect Row access examples

[sfc-gh-qding]

Summary

DOC-11506: Add collect Row access examples.

Docstring-only clarification of existing API behavior. No executable implementation, signatures, shared state, AST encoding, credentials, dependencies, logging, or telemetry changes.

Validation

Five doctest statements passed in local testing, including sorted output and indexed/named Row access. Docutils reports one existing baseline warning and no increase.

• Python AST comparison with docstrings removed confirms runtime code unchanged.
• Sphinx/Napoleon and docutils parsing: no new warnings. Repository-pinned Black 22.3.0 and git diff checks passed.
• Overlapping session.py, dataframe.py, and array_agg documentation edits merge cleanly pairwise.
• Full SDK integration and full Sphinx builds deferred to CI. Local tests used isolated Python 3.11 and Snowpark 1.55.0 with localtest; mocks are not live integration validation.

Required acknowledgments

• I acknowledge that I have ensured my changes to be thread-safe.
• If adding any arguments to public Snowpark APIs or creating new public Snowpark APIs, I acknowledge that I have ensured my changes include AST support.

NO-CHANGELOG-UPDATES: documentation-only, no runtime behavior change.

Generated with Snowflake CoCo

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.46%. Comparing base (5ab7287) to head (e6e3663).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4400      +/-   ##
==========================================
+ Coverage   95.44%   95.46%   +0.02%     
==========================================
  Files         176      176              
  Lines       45271    45271              
  Branches     7759     7759              
==========================================
+ Hits        43209    43220      +11     
+ Misses       1282     1270      -12     
- Partials      780      781       +1     

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[sfc-gh-qding]

Superseded by consolidated PR #4407: #4407 . This change is preserved in the combined branch and was revalidated with the other nine documentation fixes. Closing only this PR; the associated Jira remains open until #4407 merges.