[SYCL][E2E] Add granularity test for `sycl_ext_oneapi_virtual_mem` extension (#15848)
Based on the test plan https://github.com/intel/llvm/pull/15509, this PR
adds an e2e test checking memory granularities returned by
`get_mem_granularity`.
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Co-authored-by: Alexey Sachkov <alexey.sachkov@intel.com>
Co-authored-by: Marcos Maronas <marcos.maronas@intel.com>