Improve Cloud Trial End Handling

When the Nabucasa Cloud Trial Ends, you don’t get a Notification or a Error when trying to use cloud services. This was verify confusing until i figured it out. I think this could be improved by sending the user a warning notification and logging appropriate errors when the trial runs out and cloud services like voice assist are being used.

Didn’t you get an email? They email me when it renews.

Ah, yes you’re right! Didn’t saw that - I think a notification in the Fronted would still be helpful.