Deleting student submissions modules should be easier

[jaakkonakaza]

Notification for downloaded student submissions with option to delete the module

I think it would be convenient to be easily able to delete the dowloaded student submissions, and I think a notification would be a good way for it

[jaakkonakaza]

Also menu option for deleting all downloaded student submissions

[OlliKiljunen]

Also menu option for deleting all downloaded student submissions

Something like this, and it should work for code vault modules, too, once they've been implemented. Probably requires that modules are somehow tagged as submission modules.