Add extra size error case in CTS for USM alloc tests #2665

I've added a TODO in the CTS for urUSMDevice/Shared/HostAlloc InvalidUSMSize tests for producing a UR_RESULT_ERROR_INVALID_USM_SIZE error. The condition of size is greater than UR_DEVICE_INFO_MAX_MEM_ALLOC_SIZE is currently uncovered:

Looks like it's caused a bunch of fails, probably due to known issues with implementing UR_DEVICE_INFO_MAX_MEM_ALLOC_SIZE. I think we might just need to omit testing the upper limit on this one and let the return code be a "possible" one rather than mandatory.

Originally posted by @aarongreig in #2642 (comment)