Update on "[ET-VK] Add PushConstantDataInfo and vector to hold push constants data in DispatchNode."

This diff adds a new class called `PushConstantDataInfo` to the `DispatchNode` class in the Vulkan backend for Executorch.
This class represents a push constant data entry, which can either be a shared pointer to a tensor's uniform data with an attribute or data with a maximum size of 16 bytes.
The `write` method is also added to this class, which writes the data to a destination buffer.

Differential Revision: [D66796049](https://our.internmc.facebook.com/intern/diff/D66796049/)

[ghstack-poisoned]

Author: trivedivivek