cuepack: cues into passages that keep their timestamps

parity/cases/cuepack/unicode.ndjson

@@ -0,0 +1,4 @@
+{"start": 0.0, "end": 4.0, "text": "Le café était naïve first"}
+{"start": 4.0, "end": 8.0, "text": "東京から来た手紙には"}
+{"start": 8.0, "end": 12.0, "text": "Ἀθῆναι καὶ Μόσχα"}
+{"start": 12.0, "end": 16.0, "text": "مرحبا"}