Openshift related image generation should completely overwrite the manifest values

In the OpenShift release to support more versions for the cockroach db, currently we need to add the supported versions in the patch file https://github.com/cockroachdb/cockroach-operator/blob/master/manifests/patches/deployment_patch.yaml and also in the file https://github.com/cockroachdb/cockroach-operator/blob/master/hack/update-pkg-manifest.sh#L60.

We are using Kustomize that it is applied on the file https://github.com/cockroachdb/cockroach-operator/blob/master/manifests/operator.yaml. This causes multiple issues:

- multiple places where the versions are added;
- we are using the merge patch strategy for Kustomize and if there are **related_images env vars** or **other env vars** that are not added to Red Hat installation (not added [here](https://github.com/cockroachdb/cockroach-operator/blob/master/manifests/patches/deployment_patch.yaml)) the values from the operator.yaml are kept the way they are defined, with docker registry.

If the release with the images is specific to Openshift only, please do not add more related_images env var to the operator.yaml, add them only on the patch file.