Get rid of excessive backup videos and backup video objects for NGT

[susanodd]

Obvious.

1. The API zip archive batch video upload merely overwrites the video.

2. With the API video upload it makes use of the same command as for the Signbank interface and invokes the backup system.

Over the past months there have been an excessive number of unnecessary backups created due to repeated requests by the API due to "disappearing videos" and issues with the file system not having completed an upload and the database becoming locked, etc. (Unknown why there are sometimes 80 backup video objects and files). These need to be cleaned up.

Caution: Deleting the excess gloss video objects using "delete" invokes the backup system. Recall that the "delete" functions like an "undo" and puts the chronologically most recent backup video to be the main video. It restores the most recently uploaded video to replace the deleted video. It has always done this. It's not a delete, it's an undo.

There is already a pull request for this.