Profile transferred to second device message should go to all devices

[nicodh]

When transfering a profile to another device the "Profile transferred" message only goes into the local device messages chat of the transferring device. It would improve security if that message goes to all devices imo.

In case someone has access to one of your devices just for a short time (or finds other ways to trick you), adds another second device and deletes the "Profile transferred" message on that device. From then you would never know that there is an additional device listening to all your chats.

Yes - if someone gets access to your device he just could make a backup and transfer it to anywhere but the add second device is very fast and convenient for that kind of attack.

And a fix is easy to implement, just send the success message to SELF chat instead of device messages in

core/src/imex/transfer.rs

Line 212 in a95bf77

add_device_msg(&context, None, Some(&mut msg)).await?;

Edit: the same applies for restore from backup

[Raiden-GH]

In this context, wouldn't it also make sense to rename the feature to "Add Additional Device"? This would raise security awareness. Many users might not even know that DC allows more than two devices.
This is particularly important in DC-Desktop, as no password is required to add an additional device. Furthermore, it's a great feature that not every messenger has. Renaming would highlight it.