Added validation split.

Merge translation results. Splits: ['test', 'validation', 'dev', 'auxiliary_train'], Total items processed: 800. Replaced: 12, Appended: 387, Kept unchanged: 0. Successes: 799, Failures: 1, Empty responses: 0, Parse errors: 1, Choice mismatches: 0, Total batches: 4, Failed batches: 0

Merge translation results. Splits: ['test', 'validation'], Total items processed: 12. Replaced: 3, Appended: 3, Kept unchanged: 0. Successes: 12, Failures: 0, Empty responses: 0, Parse errors: 0, Choice mismatches: 0, Total batches: 2, Failed batches: 0