Cascading Delete for Subcollections #124
Description
Currently, when a collection is deleted, all of that collection's subcollections will be deleted as well. If a subcollection is deleted, however, its subcollection children will not be deleted.
This is due to the fact that is impossible to have self-referential queries in mongo middleware.
Implications: no functional implications except some orphaned subcollections in the database
Solution: refactor database structure to nest subcollections under collections. There is no real reason they need to be their own standalone model