Add: OkResponse class as default for successful response with no body

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/response/OkResponse.java

@@ -0,0 +1,20 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.response;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionId;
+
+/**
+ * A simple success response with an empty body.
+ *
+ * <p>Use this to acknowledge successful requests that do not carry additional payload data.
+ */
+public class OkResponse extends SuccessResponse {
+    /**
+     * Create a minimal successful response (no body content).
+     *
+     * @param sessionId the target session id
+     * @param requestId the originating request id
+     */
+    public OkResponse(SessionId sessionId, int requestId) {
+        super(sessionId, requestId, ResponseBody.builder().build());
+    }
+}