Add the pod meta fields to the CR

[voltbit]

Currently we can only trigger a rolling update/restart of the pods by changing the configuration of the container images or resources:

https://github.com/PayU/redis-operator/blob/master/controllers/rediscluster.go#L643-L654

However, the RedisCluster CR and the controller acts as a Deployment resource - they define and manage the pods directly. We could improve the support of pod rolling restart by adding a pod template inside the CR that will contain both the pod meta and pod spec and track changes of this template configuration.
This would allow triggering of rolling update on any pod change, including annotations and labels.

An alternative solution is to encapsulate each pod in a Deployment or StatefulSet and keep their pod template as field in the CR.