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!