A/V Caption files in Canvas annotations are not used, cookbook recipe does not work

[lutzhelm]

At the time A/V with captions had been implemented in Mirador, the cookbook recipe preview manifest contained the captions directly in the painting annotation body as a second entry to the video: https://github.com/IIIF/cookbook-recipes/blob/a8299877e67ff8d960b9ca82da0e959476f18e53/recipe/0219-using-caption-file/manifest.json

However, the published recipe suggests that captions should be provided as separate supplementing annotation in the Canvas annotations: https://iiif.io/api/cookbook/recipe/0219-using-caption-file/manifest.json https://preview.iiif.io/cookbook/0219-using-caption-file/recipe/0219-using-caption-file/manifest.json

Therefore the captions do not work in the video demo: https://mirador-dev.netlify.app/tests/integration/mirador/video.html