[CEL -> Expr] Examples: "Quantity"

[polds]

"Quantity" needs CEL translation.

[polds]

This requires a custom library for parsing quantities be injected into the engine. The CEL Playground uses https://pkg.go.dev/k8s.io/apiserver/pkg/cel/library which is specific to CEL.

We could adapt, find other, or remove this from the examples.