REFACTOR: Fix import functionality in attach_to_module.js

[mcflyhalf]

In the file .../static/javascript/admin_dashboard/attach_to_module.js, there should have been attach to module functionality that should have been used but wasn't because we couldn't import some required functionality from ...static/javascript/admin_dashboard/add_entity.js.

This video makes it seem very easy to do. Check it out and try to refactor this