delete action does not resture mv-default values

[karger]

The delete action is a useful way to "clear" the properties of a group. But if you delete a node which contains properties that have been changed from their mv-default values, then those properties get cleared but the default values do not get restored. If you now save and then reload the data, then the defaults do get restored since there is no value present. In other words, you will be looking at different than the data you saw when you saved. https://codepen.io/karger/pen/XWLWppb?editors=1100