feat(backend_server.py): add get_clients_data() method

src/judas_server/backend_server.py

@@ -359,3 +359,9 @@ class BackendServer:
             "status": client.status,
             "initial_telemetry": client.initial_telemetry,
         }
+
+    def get_clients_data(self) -> dict[str, dict[str, object] | None]:
+        return {
+            client_id: self.get_client_data(client_id)
+            for client_id in self.clients.keys()
+        }