Decouple user name from private key
Hello, this issue is about changing the user name. In as such, it is somewhat related to #1641, in which it is suggested to assign random usernames at account creation.
From https://twitter.com/BriarApp/status/1218153737992245248 I learnt that the user name in Briar forms part of the cryptographic identity, which comes as a surprise. It means that I cannot change my name, whether that be for legal reasons (i.e. official name change), changes to the identity with which I want to represent myself, or because I might have not thought it through when I signed up. There is a warning behind the (I), but I didn't see that.
Would it be possible to reduce the user identity to the public key (which is what pretty much every other piece of software is doing), and to keep the user name as a variable in the profile of the user, which, if changed, propagates to all connected users?