Recursive deletion of members on deletion of container

Opening this issue to start discussion on moving forward with recursive deletion of members within a containers. Related to https://github.com/solid/solid-spec/issues/172

I propose that we allow this from a specification level, this will allow for agents to remove a container without first reading & then deleting all its members.

An example of when this would be useful is seen when an agent wants to no longer utilise an application that had previously been given write access to a specific folder within the agents storage pod, the user may not have rights to all directories within that container, but its still their storage pod to do whatever they please with. If we allow recursive deletion, it means that the agent doesn't need to have read or write access to those member resources, but can still delete the entire folder.