[USERHUB_backend] lambda to fetch videos by state and by state-userID

[sherif98]

Do we need this? We might be able to fetch all videos and just do the grouping on frontend in admin dashboard? Or should we query the GSI (by state) and fetch videos (e.g. pending)

[sherif98]

We need to coordinate with Andrius on how the dashboard will work. As a first iteration we might just start with front end filtering and see if it causes any performance issues