Add sycl_ext_oneapi_work_group_scratch_memory to the supported extensions list

[dvrogozh]

The sycl_ext_oneapi_work_group_scratch_memory is currently experimental extension while actual products such as Pytorch rely on it in the shipped products. Can this extension be promoted from experimental to supported?

See: https://github.com/intel/torch-xpu-ops/blob/release/2.14/src/comm/SYCLHelpers.h#L288
CC: @gmlueck, @EikanWang, @guangyey

[gmlueck]

We have discussed this already with the Khronos WG, and there is no opposition to making it a KHR.

This extension has a dependency on "properties", though, so we first need to make a KHR for properties. That is already in progress (KhronosGroup/SYCL-Docs#980).