test, utils, visualizer: document missing functions and variables in scripts

Silences warnings on Doxygen > 1.9.7.

utils/python-unit-tests.py

@@ -414,6 +414,7 @@ class TestSimulator(unittest.TestCase):
                 return None
                 """
                 super().__init__()
+                ## __python_owns__ flag indicates that Cppyy should not manage the lifetime of this variable
                 self.__python_owns__ = False  # Let C++ destroy this on Simulator::Destroy
                 ## Listen port for the server
                 self.port = port