Code Review

This pull request introduces the dml_last_statement_option function to both standard and PostgreSQL-dialect Spanner snippets, along with corresponding CLI command support and tests. The review feedback identifies a potential logic error in pg_snippets.py where a renamed subparser command may not be correctly handled in the command dispatch logic. Additionally, the reviewer suggested improvements for region tag placement to maintain consistency, fixed typos in docstrings, and recommended cleaning up extra spaces in SQL string concatenations.