Migrate to kubebuilder go/v4 project layout

[skitt]

Operator SDK 1.38 drops support for the go/v3 project layout, which is the layout currently used in the Submariner operator. To upgrade to 1.38, the project needs to migrate to go/v4, either by creating a new v4 project and copying the APIs and code to the new layout, or by moving the relevant files to the new layout.

See the v1.38.0 release notes for details.

[dfarrell07]

@skitt What prio/timeline do you think this should be done in?

[skitt]

I don’t think there’s any rush, but as usual with SDK changes, the longer it gets pushed back, the harder it will likely be to catch up.