[MaxPooling] Add support for ceil_mode parameter.

Add support for onnx ceil_mode paramter which determine the rounding function used to compute the output shape.

aidge_core/unit_tests/test_operator_binding.py

@@ -102,5 +102,30 @@ class test_operator_binding(unittest.TestCase):
         genOp.get_operator().compute_output_dims()
         self.assertListEqual(genOp.get_operator().output(0).dims(), in_dims)
 
+    def test_set_impl(self):
+
+        class PythonCustomImpl(aidge_core.OperatorImpl):
+            """Dummy implementation to test that C++ call python code
+            """
+            def __init__(self):
+                aidge_core.OperatorImpl.__init__(self) # Recquired to avoid type error !
+                self.idx = 0
+
+            def forward(self):
+                """Increment idx attribute on forward.
+                """
+                self.idx += 1
+
+        generic_node = aidge_core.GenericOperator("Relu", 1, 1, 1, name="myReLu")
+        customImpl = PythonCustomImpl()
+        generic_op = generic_node.get_operator()
+
+        generic_op.forward() # Do nothing, no implementation set
+        generic_op.set_impl(customImpl)
+        generic_op.forward() # Increment idx
+        self.assertEqual(customImpl.idx, 1)
+
+
+
 if __name__ == '__main__':
     unittest.main()