Replace favorites entities with a PreferencesManager, that returns
observables for:
- Module preferences (by module UUID)
- Provider preferences (by ProviderID)
Automate preferences availability in:
- Module views (empty for now)
- VPN server view (favorites)
Synchronize preferences by making this a CloudKit container. Preferences
are also available in the Tunnel by storing the container in the App
Group.
Some providers require specific credentials for OpenVPN, different from
account credentials. Update the API index with this information to show
an information footer and possibly a link to the OpenVPN credentials.
Also, fix the OTP footer not appearing on macOS.
Davide