Force filtering queryset on current related object in each viewset

[lunika]

Purpose

Every viewset managing a resource related to an other (thumbnail -> video, classroom documents -> classroom) are now accessible using nested URL and we have no control anymore on the current resource because the JWT token is based on the playlist on a LTI context. Every queryset must be filtered using the current related resource in the url.

Proposal

• [x] filter classroom documents queryset
• [x] filter deposited file queryset
• [x] filter thumbnail queryset
• [x] filter timed text track queryset
• [x] filter shared live media query set