Wrapping onnx structs about connxr

[nopeslide]

One thing I have in mind is to add a void pointer to all our (onnx) structures which can be used when cONNXr is integrated in some other codebase to easily extend it without replacing internal allocation code.
I.e.: a custom scheduler could then annotate these tensors to determine how they depend on each other.

[alrevuelta]

Right, this is essentially what we did with node_context and Onnx__NodeProto. Its a fair suggestion but tbh I don't really foresee any extension, so I would leave as it is by now and focus our efforts somewhere else. If in the future we find the need, we can of course wrap it.

[nopeslide]

I would like to do it in near future, since I need to integrate connxr in another framework and therefore need to replace/extend a few things.

[alrevuelta]

If you have already thought a particular use case I'm fine with it.