Draft: Add new API to retrieve GPU stats (AMD & NVIDIA)

Retrieves both AMD and NVIDIA stats

Intel - no non-sudo monitoring mechanism so it will never be part the new API

Largely based on the work of @siavashs for AMD see !16

Included only the most important gpu stats:

• number of gpus
• gpu core busy percentage
• gpu vram memory total
• gpu vram usage bytes

Added also gpu info such as:

• gpu name
• bus id

Signed off: Dr. James Dominic P. Guana jdpguana@histark.com