[ADD] added chat to all method from docter, it works but there is sometimes an error in the doctor client app that the buffer in OnRead is full, so will try to fix that tomorrow

DoctorApp/ViewModels/ClientInfoViewModel.cs

@@ -77,6 +77,7 @@ namespace DoctorApp.ViewModels
 
             ChatToAll = new RelayCommand<object>((parameter) =>
             {
+                Debug.WriteLine("[CLIENTINFOVIEWMODEL] sending message to all clients");
                 this.parent?.SendToAllClients(((TextBox)parameter).Text);
             });