Improve update detection for .NET (Core) applications deployed with ClickOnce

.NET (Core) applications deployed with ClickOnce cannot use `ApplicationDeployment` class for on-demand update check.

Besides checking for new updates, this check can be used to ensure that the deployment is still available on the server and wasn't deleted. If application is doing silent updates, without this check, user won't be aware that application is not getting any updates.

Launcher could do the update check if application is configured to install new updates automatically. We need to find a way to communicate the result of this check to .NET (Core) application. We could potentially also include the result of any recent automatic update.