[ET-VK][BE][ez] vTensor cleanup 1/N - swap order of vTensor and vTensorStorage in cpp file

## Context

TSIA; swap the order of `vTensorStorage` and `vTensor` function implementations in the `Tensor.cpp` file, such that it matches the order of declaration in the `Tensor.h` header file. I don't recall why the ordering was not consistent before.

Differential Revision: [D62878648](https://our.internmc.facebook.com/intern/diff/D62878648/)

[ghstack-poisoned]

Author: SS-JIA