The user summary's delete button UX relied on the "admin-user.js" destroy function, which was called through the "admin-tools" service. After #11724, we no longer put UX behavior on Ember models.
Users could be silenced or suspended by two staff members at the same time and
would not be aware of it. This commit shows an error message if another penalty
has been applied.
Roman Rizzi
Krzysztof Kotlarek
Vinoth Kannan
Bianca Nenciu
Mark VanLandingham
Robin Ward