Allow passing arguments to NVIDIA GPU Operator

For the NVIDIA GPU Operator, Addon users should be able to specify some important arguments such as:

- container runtime (`docker` / `crio` / `containerd`)
- default GPU mode (`passthrough` / `baremetal` / `vgpu`)

For this, the best approach may be to separate the NVIDIA GPU operator / AMD GPU Device Plugin into separate addons.

Start by locating the NVIDIA GPU Operator and AMD GPU Device Plugin addon definitions, then trace how addon users currently configure operator settings. Define how container runtime and GPU mode values should be exposed and whether the addons must be separated. Done means users can provide both requested arguments with supported values.

Written by the indexing model from the issue text.