Fixes issue where identity names were not saved when switching between
multiple identities. Names were being saved to master settings instead
of user-specific settings.
Changes:
- UserNameDialog: Load/save names from/to user-specific settings
- NewEditAccountView: Save names to user-specific settings for active DID
- Both components now use $accountSettings() and $saveUserSettings()
instead of $settings() and $updateSettings()
Each identity now properly retains their assigned name when switching
between identities. Previously only "User Zero" would show their name
due to using master settings instead of per-identity settings.
Fixes: Identity name persistence across identity switches
