The current behaviour when deleting a SeataServer CR is to preserve the volume claimed by associated Statefulset. It would be nice to add an option for user to control the volumn recalim behaviour.

My idea is to add a new volumeReclaimPolicy property inside store structure, and make valid values ("Delete", "Retain"). "Retain" stands for current implementation, whereas "Delete" stands for delete associated volumns when deleting the SeataServer CR. It is recommended to use Kubernetes finalizer to implement the "Delete" policy.