Resource references are not raising CollectionChanged event

[dbeuchler]

Describe the bug
Resource references are not raising CollectionChanged event

To Reproduce
Steps to reproduce the behavior:

public IReferences<IMyResource> MyResources { get; set; }

protected override void OnStart()
{
    var refCol = (IReferenceCollection)MyResources;
    refCol.CollectionChanged += RefColOnCollectionChanged;
}

private void RefColOnCollectionChanged(object sender, ReferenceCollectionChangedEventArgs e)
{
    // not raised
}

Add resource to the references and save. Nothing happens.

Expected behavior
CollectionChanged event should be raised.