Automatic merge from submit-queue (batch tested with PRs 54436, 53148, 55153, 55614, 55484). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

code-generator: complete PkgName, GroupName, GoName seperation

... in client-gen, informer-gen, lister-gen. Follow-up of https://github.com/kubernetes/kubernetes/pull/54950.

Before this PR, the generated code was broken for internal types and for group package names that were no valid Go identifiers.

This PR completes the separation in the following sense:

- GroupNames are domain-like logical name for the group. Only the first segment is used as default for GoName
- PkgName is the directory name. All packages in client, informer, lister re-use this for packages.
- GoName is the Go identifier (CamelCase) used to reference the group, e.g. in the interface names, in the clientsets etc. Moreover it is used for package import aliases.

Note: this PR **does not** change the generated code in Kubernetes, only the examples in k8s.io/code-generator.

```release-note
Fix code-generators to produce correct code when GroupName, PackageName and/or GoName differ.
```