Bind compute dims

Feature:

• Allow to define the computation of output dimension using a python function

Usage:

import aidge_core
w0 = aidge_core.Producer([25, 25], name="W0")
matmul0 = aidge_core.GenericOperator("MatMul", 1, 1, 1, name="MatMul0")
graph_view = aidge_core.sequential([w0, matmul0])
def myComputationMethod(a):
    print(a)
    return a
matmul0.get_operator().set_compute_output_dims(myComputationMethod)
matmul0.get_operator().compute_output_dims()

• Add identity function to the binding. usefull ? (equivalent to lambda x:x```which is shorter than aidge_core.GenericOperatorOp.identity``...)
• Add unittest

aidge_core/unit_tests/test_operator_binding.py

@@ -61,5 +61,15 @@ class test_operator_binding(unittest.TestCase):
         self.generic_operator.add_parameter("l_str", ["ok"])
         self.assertEqual(self.generic_operator.get_parameter("l_str"), ["ok"])
 
+    def test_compute_output_dims(self):
+        in_dims=[25, 25]
+        input = aidge_core.Producer(in_dims, name="In")
+        genOp = aidge_core.GenericOperator("genOp", 1, 1, 1, name="genOp")
+        _ = aidge_core.sequential([input, genOp])
+        self.assertListEqual(genOp.get_operator().output(0).dims(), [])
+        genOp.get_operator().set_compute_output_dims(lambda x:x)
+        genOp.get_operator().compute_output_dims()
+        self.assertListEqual(genOp.get_operator().output(0).dims(), in_dims)
+
 if __name__ == '__main__':
-    unittest.main()
\ No newline at end of file
+    unittest.main()