Add docstring examples for Scalar string functions (#1423)

* Add docstring examples for Scalar string functions

Add example usage to docstrings for Scalar string functions to improve documentation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Remove examples for aliases

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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: ntjohnson1