Add log_note execution option

The PR adds _get_log_note as an abstract method on ExecutionContext with no default implementation (raises NotImplementedError). Only DefaultExecutionContext provides an implementation. Any third-party dialect or custom context that subclasses ExecutionContext directly (not DefaultExecutionContext) will raise NotImplementedError when self._echo is True and logging occurs. This is a breaking change for such subclasses and will cause runtime errors in production if logging is enabled. The fix is to provide a default implementation in ExecutionContext that returns "" (empty string) to maintain backward compatibility.