[FLINK-40203][runtime] Add an explicit option for Flink SQL-compatible YAML Transform expression semantics

[haruki-830]

Summary

This commit adds an explicit expression semantics option to YAML Transform. The default LEGACY mode preserves existing pipeline behavior, while the opt-in FLINK_SQL mode aligns supported predicates with Flink SQL semantics.

Key Changes

1. Configurable Transform Expression Semantics

• Added the pipeline.transform.expression.semantics option.
• Added LEGACY as the default value to preserve backward compatibility.
• Added FLINK_SQL as an opt-in mode for Flink SQL-compatible expression evaluation.
• Propagated the configured semantics through the composer and Transform runtime.

2. Flink SQL-Compatible Predicate Semantics

• Added SQL three-valued logic for =, <>, <, <=, >, and >=.
• Added SQL-compatible BETWEEN / NOT BETWEEN and IN / NOT IN behavior.
• Represents SQL UNKNOWN as a nullable Boolean.
• Changed two-argument LIKE / NOT LIKE to use SQL % and _ wildcards with whole-string matching.
• Keeps rows in Transform filters only when the result is TRUE, while projections preserve UNKNOWN as NULL.

3. Test Coverage and Documentation

• Added runtime unit tests for both legacy and Flink SQL semantics.
• Added YAML Transform specs covering comparison, BETWEEN, IN, LIKE, and row-level filtering with UNKNOWN.
• Added YAML configuration parsing coverage for the new option and its default value.
• Documented the configuration and behavioral differences in both English and Chinese.

JIRA Reference

https://issues.apache.org/jira/browse/FLINK-40203