misc s3 cleanup

[Ardiea]

Description/Context

mitx-elasticsearch-backups-operations-es7
mitx-elasticsearch-backups-operations-es6
mitx-site-archive
ttvmit-ttv-videos
mitx-on-edx-data-archive
mitx-elasticsearch-backups

The elasticsearch backups can probably be removed outright but the others need deeper considerations. They could at least benifit from a different storage tier configuration. Refer to vantage on how much they are used (if at all) and what can be saved by using intelligent archiving and if it makes sense.

Plan/Design