Add missing definitions of global permissions

• alsijil.view_lesson
• alsijil.view_full_register
• alsijil.edit_personalnote → alsijil.change_personalnote
• alsijil.assign_grouprole
• core.view_full_register → alsijil.view_full_register
• Register core.assign_grouprole for group

This has no security side effects, as users just weren't able to see some things, but not to see things they shouldn't.