Add support for launching apps using the command line from Windows

Launching an app from the command line from Windows doesn't work at the moment.

We should look into figuring out how to do this.

~One complexity is that .NET handles "dotnet run" by doing something like executing "$RunCommand $RunArguments" (we can't execute a custom target).~ (now we can)

One idea around this would be to just execute dotnet again and specify the custom target (which would remote to the the Mac), so something like this:

RunCommand="dotnet"
RunArgumens="build /t:ExecuteMlaunch '/p:MlaunchArguments=$RunArguments'"

See also https://github.com/xamarin/xamarin-macios/issues/12459.