Update on "[ET-VK][9/n] clone node"

Introduce a clone node for copy operation.

Also register `aten.clone` to this node. Important to note that during model export, possible to point the lvalue of `aten.clone` to the underlying shared object of the rvalue to achieve no-copy.

Differential Revision: [D56441547](https://our.internmc.facebook.com/intern/diff/D56441547/)

[ghstack-poisoned]

Author: yipjustin