Friendly user name support

When registering a FIDO authenticator, the user can select a display name for their account. The app then displays this user display name instead of the automatically generated, unique user name. For details see Registering FIDO Authenticators in the iOS, Android, and Web Developer Guides. You can also prompt the user to name an individual authenticator, to help them distinguish between multiple FIDO2 authenticators. See Prompting the User to Name a Security Key in the iOS, Android, and Web Developer Guides. User names can also be controlled using an API Server Plugin, see Create a Session Plugin.