Analyse and Replace kubernetes API deprecations

The operator contains and still uses deprecated API. Although, it would appear that written code has already been migrated, eg. kind: Deployment coming from app/v1 API, there are a number of uses of extensions/v1beta1, apps/v1beta1 and apps/v1beta2 in the operator's dependencies located in the vendor directory.

With the introduction of Openshift 4.3, deprecation warnings are being generated against the operator. Mitigating action is detailed by kubernetes here.