feat: implement self-signed certificate support in API and UI

- Added support for self-signed TLS certificates in the ApiService, allowing configuration based on server settings.
- Introduced a toggle in the ServerConnectionPage to enable or disable trusting self-signed certificates.
- Updated localization files to include new strings for self-signed certificate settings in multiple languages.
- Enhanced the OptimizedStorageService to manage trusted servers based on user preferences for self-signed certificates.
- Improved error handling and logging throughout the affected services to ensure clarity and maintainability.

lib/l10n/app_localizations_it.dart

@@ -756,6 +756,14 @@ class AppLocalizationsIt extends AppLocalizations {
   String get customHeadersDescription =>
       'Aggiungi header HTTP personalizzati per autenticazione, chiavi API o requisiti speciali del server.';
 
+  @override
+  String get allowSelfSignedCertificates =>
+      'Considera attendibili i certificati autofirmati';
+
+  @override
+  String get allowSelfSignedCertificatesDescription =>
+      'Accetta il certificato TLS di questo server anche se è autofirmato. Attiva questa opzione solo per server di cui ti fidi.';
+
   @override
   String get headerNameEmpty => 'Il nome header non può essere vuoto';