Automatically dispatch `CanExecuteChanged` event to the UI thread

[ptasev]

Is your feature request related to a problem? Please describe.

Manually dispatching this event to the UI thread adds boilerplate to the view models and can cause confusion or frustration when a new user of the framework doesn't understand why things are breaking. See #7644

Describe the solution you'd like

The UI framework performs checks to see if the event is called on the UI thread, and if not then dispatches it automatically. Similar to #10362 for PropertyChanged event.

Describe alternatives you've considered

No response

Additional context

No response

[timunie]

Can you share a minimal sample how you use it? It should only be needed rarely.

[ptasev]

I'm getting a status asynchronously from a SignalR server using HubConnection.On(...). When the status updates the view model property it also triggers CanExecuteChanged on several commands. This status indicates the mode of operation on a hardware device and hence what commands are currently allowed to run.

I thought it'd be nice to automatically handle these in the UI internals rather than having to Post to the UIThread. It's a good opportunity to standardize the logic for handling this event in the 4 - 6 controls that handle it.