Move From/ToCRI out of NRI so as to not leak the CRI versioning issues into NRI

In evaluating some CRI vendoring problems with kubernetes... @dmcgowan brought up the fact that we have leaked CRI over into NRI. This does not seem necessary. Let's move these From/To CRI linux resources functions over into the internal CRI implementation so as to not leak CRI vendoring/versioning issues.

https://github.com/containerd/nri/blob/main/pkg/api/resources.go#L84

https://github.com/containerd/containerd/blob/86d68096d2d033c0f161e869af8b69fbb05c6f7f/internal/cri/nri/nri_api_linux.go#L615

@klihub thoughts?

Read pkg/api/resources.go around line 84 and containerd's internal/cri/nri/nri_api_linux.go around line 615. Trace the From/To CRI Linux resource functions and their callers. Done means CRI-specific resource conversion is confined to the internal CRI implementation without leaking CRI vendoring or versioning concerns into NRI.

Written by the indexing model from the issue text.