GTEST/COMMON: Added test for cuda async allocated buffers.

[rakhmets]

What

Extended UCP AM RNDV tests by adding buffers allocated by cudaMallocAsync.

[brminich]

some CI errors are relevant:

/__w/1/s/ucx_src_89282/contrib/../test/gtest/common/mem_buffer.cc: In static member function 'static void* mem_buffer::allocate(size_t, ucs_memory_type_t, bool)':
/__w/1/s/ucx_src_89282/contrib/../test/gtest/common/mem_buffer.cc:242:23: error: 'cudaMallocAsync' was not declared in this scope
             CUDA_CALL(cudaMallocAsync(&ptr, size, 0), ": size=" << size);
                       ^