Use KAL linter for Kubernetes API definitions

[czeslavo]

Problem Statement

Defining Kubernetes API via Go types has its pitfalls. Some of them can be caught using a new KAL linter: https://github.com/JoelSpeed/kal.

Inspired by #238 (comment).

Proposed Solution

Use KAL as a standalone binary (as of now, it's not part of the golangcilint suite, so that should be the easiest way for now - we can migrate once it's included).

Acceptance Criteria

• All Kubernetes API types defined in this repository are linted using https://github.com/JoelSpeed/kal

[pmalek]

Linter location has moved to https://github.com/kubernetes-sigs/kube-api-linter (original link still works with a redirect to said new location).