fix: component-set-handle-list-tools (#4465)

update component.py

I added a StructuredTool to define the set function in the component. This change resolved an error that occurred when the list of tools was set by the component. In the future, we may need to add tests to manage unexpected situations in the component's set function.

I also updated the pytest.

src/backend/tests/unit/components/agents/test_agent_component.py

@@ -24,5 +24,5 @@ async def test_agent_component_with_calculator():
         temperature=temperature,
     )
 
-    response = await agent.get_response()
+    response = await agent.message_response()
     assert "4" in response.data.get("text")