Etcd maintenance

[makhov]

To prevent issues with etcd we probably need to:

• enable autocompaction
• run defrag periodically

Aenix etcd-operator suggests using the following default values for autocompaction (https://github.com/aenix-io/etcd-operator/issues/222):

auto-compaction-mode: "periodic"
auto-compaction-retention: "5m"
snapshot-count: "10000"

Example defrag CronJob: https://github.com/ahrtr/etcd-defrag/blob/main/doc/etcd-defrag-cronjob.yaml