Update on "[ET-VK] Rearranging code in permute op shader to reduce heavy math ops and improve performance."

The diff rearranges Permute op shader code in executorch vulkan backend to reduce heavy math operations and improve performance. The change also include adding an extension to support explicit arithmetic types and changing the data type of the position variable to u16vec3.

Differential Revision: [D66174765](https://our.internmc.facebook.com/intern/diff/D66174765/)

[ghstack-poisoned]

Author: trivedivivek