refactor(sentry): standardize exceptions to prevent Sentry minification

lib/features/mailbox_dashboard/data/datasource_impl/session_storage_composer_datasoure_impl.dart

@@ -39,7 +39,7 @@ class SessionStorageComposerDatasourceImpl
           .map((entry) => ComposerCache.fromJson(jsonDecode(entry.value)))
           .toList();
       } else {
-        throw NotFoundInWebSessionException();
+        throw const NotFoundInWebSessionException();
       }
     }).catchError(_exceptionThrower.throwException);
   }