[Request] App Lifecycle Events with MVVM and/or SignalR connections

I am searching for an example/best practice of handling application lifecycle events in ViewModels to control for example SignalR connections.

I want to do something like close SignalR connection on ```Stopped``` Event and reconnect on ```Resumed``` Event.

My usecase is a Dashboard App with some different ContentViews each showing values from different areas. Each area has it's own View, ViewModel, Model

Start with issue #274's request for application lifecycle handling in ViewModels, especially the Stopped and Resumed events and SignalR connections. Determine the appropriate existing sample entry point, then define a minimal MVVM example whose completed behavior demonstrates closing on Stopped and reconnecting on Resumed.

Written by the indexing model from the issue text.