Fix Reshape

Context

Fix Reshape operator:

• Handle case where a dimension is 0 (see ONNX)
• Support both cases where the shape is either an input or an attribute

Modified files

• Reshape.hpp, Reshape.cpp, and pybind_Reshape.cpp;

include/aidge/operator/Reshape.hpp

@@ -45,7 +45,7 @@ public:
     using attr = typename Attributes_::template attr<e>;
 
     Reshape_Op(const std::vector<std::int64_t>& shape)
-        : OperatorTensor(Type, 1, 0, 1),
+        : OperatorTensor(Type, 2, 0, 1),
           Attributes_(attr<ReshapeAttr::Shape>(shape))
     {
         mImpl = std::make_shared<Reshape_OpImpl>(*this);
@@ -87,7 +87,7 @@ public:
     }
 };
 
-inline std::shared_ptr<Node> Reshape(const std::vector<std::int64_t>& shape,
+inline std::shared_ptr<Node> Reshape(const std::vector<std::int64_t>& shape = {},
                                    		const std::string &name = "") {
     // FIXME: properly handle default w&b initialization in every cases
     return std::make_shared<Node>(std::make_shared<Reshape_Op>(shape), name);