refactored _get_not_assigned_usages to remove loop (#2984)
refactored _get_not_assigned_usages to remove loop (#2984)


eduNEXT/edunext-ecommerce,eduNEXT/edunext-ecommerce,edx/ecommerce,edx/ecommerce,eduNEXT/edunext-ecommerce,eduNEXT/edunext-ecommerce,edx/ecommerce,edx/ecommerce