Support non-default dim orders in pybindings + aten bridge (#9736)

Summary: Now that we have better dim order support, we can pass inputs
into models in non-default dim orders, such as channels last. This works
in the runtime, but the python layer current asserts that input tensors
are in default dim order. This PR relaxes this restriction to allow
dense input tensors with alternative dim orders.

Differential Revision: D71716100