@Immutable

[teyckmans]

Add @immutable annotation to attributes that are documented to be immutable or that we have/gain knowledge about that can not be updated.

This would allow KubeRig to detect changes on immutable fields and first remove the resource before creating again instead of just applying the update.

This applies for example to the host and tls attributes of OpenShift Routes.

[teyckmans]

We should support an extensible way for users to add immutable information, something like jackson annotation mixins. To allow users to unblock themselves in case the information is not yet contained within kuberig-dsl itself.