No player thumbnails when master has no `duration` tag

[ntarocco]

There are master videos that do not have the tag duration in the extracted metadata, for example: https://videos.cern.ch/record/1255874

As result, the creation of the vtt file for the video player fails. See Sentry issue 294 (https://test-cds-sentry.web.cern.ch/sentry/videos/issues/294/)

[ludmilamarian]

@ntarocco what would be a good query to check how many we have from the interface? https://videos.cern.ch/search?page=1&size=21&q=NOT%20_files.0.tags.duration gives me only the ones without the master. Otherwise I will check in the DB, no worries.

[ntarocco]

It looks like (or I didn't find) to query for specific array indexes, answers to these questions in ES forum suggest to create dedicated fields to resolve this issue... I think we have to loop in the db...