feat: implement account switcher component and state management

- Add AccountSwitcher component for managing user accounts with UI for switching, adding, and logging out.
- Create account state manager to handle snapshots of account-specific states for efficient switching.
- Introduce utility functions for account management, including ID generation and avatar color assignment.
- Implement Zustand store for account management, supporting addition, removal, and state retrieval of accounts.

locales/fr/common.json

@@ -34,6 +34,9 @@
     "dismiss": "Fermer",
     "or": "ou",
     "sign_in_sso": "Se connecter avec SSO",
+    "add_account_title": "Ajouter un compte",
+    "add_account_subtitle": "Se connecter avec un autre compte",
+    "cancel": "Annuler",
     "website": "Site web",
     "imprint": "Mentions légales",
     "privacy_policy": "Politique de confidentialité",
@@ -58,6 +61,11 @@
     "storage_free": "Libre",
     "storage_total": "Total",
     "sign_out": "Se déconnecter",
+    "sign_out_of": "Se déconnecter de {account}",
+    "sign_out_all": "Se déconnecter de tous les comptes",
+    "add_account": "Ajouter un compte",
+    "set_as_default": "Définir par défaut",
+    "switch_account": "Changer de compte",
     "contacts": "Contacts",
     "calendar": "Calendrier",
     "settings": "Paramètres",