Missing preferred work-group size multiple query on device

Right now it's possible to query the `kernel` for `kernel_device_specific::preferred_work_group_size_multiple` (see [Table 136. Device-specific kernel information descriptors](https://registry.khronos.org/SYCL/specs/sycl-2020/html/sycl-2020.html#_kernel_information_descriptors)), which in OpenCL corresponds to [CL_KERNEL_PREFERRED_WORK_GROUP_SIZE_MULTIPLE](https://registry.khronos.org/OpenCL/specs/3.0-unified/html/OpenCL_API.html#CL_KERNEL_PREFERRED_WORK_GROUP_SIZE_MULTIPLE), but it's not possible to query the `device` for the preferred work-group size. That number might be different, and it should be slightly easier to obtain than the kernel one. It would correspond to the OpenCL parameter [CL_DEVICE_PREFERRED_WORK_GROUP_SIZE_MULTIPLE](https://registry.khronos.org/OpenCL/specs/3.0-unified/html/OpenCL_API.html#CL_DEVICE_PREFERRED_WORK_GROUP_SIZE_MULTIPLE).

Though, the device query is specific to OpenCL 3.0, so there might need to be a way to specify a default for when the device doesn't support this query.

Start by comparing the existing kernel_device_specific::preferred_work_group_size_multiple documentation with the SYCL and OpenCL descriptors linked in the issue. Determine how a device-level query and a default for devices without the OpenCL 3.0 query should be specified. Done means the relevant SYCL specification text clearly defines the query and fallback behavior.

Written by the indexing model from the issue text.