This is a first step to globalize how toasts are treated in the qml layer:
- Created `ToastsManager.qml` class to deal with all app toasts generation.
- Started moving community transfer ownership related toasts to the new manager class.
- Some small cleanup in `AppMain.qml`
Nim backend:
- Created new api method to deal with extended / action toasts.
- Updated needed model / item with new needed roles.
Closes of #12175
Noelia