test: increased cb test coverage

test/unit/schemas/test_message.py

@@ -0,0 +1,12 @@
+from control_backend.schemas.message import Message
+
+
+def base_message() -> Message:
+    return Message(message="Example")
+
+
+def test_valid_message():
+    mess = base_message()
+    validated = Message.model_validate(mess)
+    assert isinstance(validated, Message)
+    assert validated.message == "Example"