Adding nstream example using oneDPL

[reble]

Which kernels are implemented?

• [ ] synch_p2p (p2p)
• [ ] stencil
• [ ] transpose
• [x] nstream
• [ ] dgemm
• [ ] reduce
• [ ] sparse
• [ ] branch
• [ ] random
• [ ] refcount
• [ ] synch_global
• [ ] PIC
• [ ] AMR

Documentation and build examples

New nstream example is using oneAPI DPC++ Library. Implementation inspired by STL and SYCL USM example. Works with existing oneAPI build configuration.

Do you certify that your contribution is made in good faith and does not attempt to introduce any negative behavior into this project?

• [x] Yes
• [ ] No

[jeffhammond]

Cool. Thanks!

I should know this, but is there no oneDPL vector class that can be used instead of a SYCL buffer, similar to Thrust? (https://docs.nvidia.com/cuda/thrust/index.html#vectors)