Improvements to align CTS and Spec for Memory

[martygrant]

intel/llvm#15619

• Add tests for UR_RESULT_ERROR_INVALID_NULL/HOST_POINTER for urMemImageCreate and urMemBufferCreate
• Add missing error condition to spec for urMemImageCreate for checking type of image description struct
• Add tests for UR_RESULT_ERROR_INVALID_NULL_HANDLE/POINTER for urMemBuffer/ImageCreateWithnativeHandle
• Remove skip for urMemImageCreateWithNativeHandle - buffer was invalid as it was never instantiated in fixture struct
• Update image format used in urMemImageTest fixture as it was invalid and likely to cause previously skipped test to fail (which now pass)
• Add missing DDI table entry for urMemImageCreateWithNativeHandle for OpenCL
• Add test for using different ur_mem_flag_t flags with urMemBufferPartition
• Add missing UR_MEM_INFO_REFERENCE_COUNT to spec for urMemGetInfo and added test for this in urMemRetain/Release
• Removed assert in L0 urMemGetInfo which would fail if mem type is not image or the query is not a context query
• Fixed potential bug with HIP urMemGetNativeHandle which would fail if the mem handle was an image because use of std::variant

[martygrant]

@RossBrunton @hdelan @PietroGhg apologies you all reviewed a previous PR (#2177) for this change but I rebased a number of times fighting with CI failures and made some changes so though it would be good to just have it reviewed afresh. The main notable change is in the hip adapter so image buffer types can be handled in urMemGetNativeHandle, and not letting some tests pass when entry points are unsupported if they aren't optional.