Offer direct-to-gpu decode

[ap--]

Everything is in place to provide nvjpeg decode directly to gpu memory. I just need to find some spare time to implement the required glue...

• [ ] provide compatible API to chose gpu decoder
• [ ] start with svs support for simplicity
• [ ] loudly fail in untested cases
• [ ] provide good benchmarks for publicly available files

via GIPHY

[464hee]

Thank you for your work and I am very much looking forward to this feature!