[etcd-backup-restore]

Most notable changes

• [USER] Updated etcd vendoring version to 3.3.13. (#157, @shreyas-s-rao)
• [USER] Full snapshot on etcd startup will now be deferred in favour of an initial delta snapshot, followed by a full snapshot and subsequent delta snapshots. (#157, @shreyas-s-rao)

Improvements

• [OPERATOR] Optimized WAL verification memory usage. (#157, @shreyas-s-rao)