whether to delete etcd data when deleting Karmada instance

[calvin0327]

when install karmada instance with hostPath to karmada etcd. we not delete the data of ectd currently when delete karmada instance. if we create a new instance named the same string with previous instance. there are dirty data on new karmada instance.

so, we should designe a optional to handle whether to delete etcd data. wolcome to discussion