Enhance failure messages
When a user send a message to a contact, the status of this message can change to "failed". The major problem here, is, (as discussed in https://git.ring.cx/savoirfairelinux/ring-project/issues/517) it's totally unclear for the user why the message failed.
The failed status MUST be re-designed to explain what is wrong for the user.
Is it a network issue? A confirmation timeout? Because no devices is detected? etc.