[vulkan] Remove ATen dependencies in vTensor class (#91022)
This diff removes all dependencies on ATen from the vTensor class, in preparation for moving the class to the `api/` folder so that it can be part of the core library (i.e. part of the `torch_vulkan_api` target introduced in the below diff which should have no dependencies on ATen.
Most notably, the constructor of `vTensor` is changed to
```
vTensor(
api::Context* context,
IntArrayRef sizes,
const c10::ScalarType dtype = c10::kFloat,
const api::StorageType storage_type = api::StorageType::TEXTURE_3D,
const c10::MemoryFormat memory_format = c10::MemoryFormat::Contiguous);
```
Instead of accepting a `TensorOptions` argument, since `TensorOptions` is a part of ATen. The majority of changes in this diff are due to updating vTensor construction to use the new constructor.
Differential Revision: [D42049862](https://our.internmc.facebook.com/intern/diff/D42049862/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91022
Approved by: https://github.com/kimishpatel
