MAUI Snack - Add WeakEventManager to MVVM Toolkit!

Johan begins by showing how MVVM Toolkit attributes simplify view model code, then points out a gap he missed from Xamarin Community Toolkit: built-in weak event handling for property change notifications.

He proposes a BaseObservableObject approach that inherits from ObservableObject and intercepts INotifyPropertyChanged and INotifyPropertyChanging events through WeakEventManager, giving MAUI apps safer event subscriptions without abandoning MVVM Toolkit patterns.