Throw warning for user configurations that reference deprecated fields

[leochr]

Liberty Operator CRDs embed various APIs (k8s, go, third-party) and as we update the dependency versions, some fields are deprecated to be removed later. It'll be good to output warning for the use of such deprecated APIs in the user configurations (CRs), so that users remove the references to the deprecated API and switch to the new API. This will prevent their configuration from becoming invalid when the deprecated API is later removed and potentially disrupt their applications.

One such example is the deprecation of BearerTokenSecret and BearerTokenFile in Prometheus (monitoring) APIs. But there are likely others (search for 'deprecate' in CRDs).
https://github.com/application-stacks/runtime-component-operator/blob/f0681bdaf060ce2979bbd4ec2c16f1425d70277e/utils/utils.go#L1211

We should throw a warning for use of deprecated fields of our Operators as well (i.e. .spec.serviceAccountName)