Enabled automatic snapshots through management API

[dokterbob]

• Enable daily snapshots
• Enable email notifications on failure
• Test daily snapshots
• Remove cronjob
• Enable retention policy (max_age: 7d, min_count: 7)
• Test retention policy
• Enable weekly snapshots
• Test weekly snapshots
• Enable retention policy (max_age: 4w, min_count: 4)
• Test retention policy
• Enable monthy snapshots
• Test monthly snapshots
• Enable retention policy (max_age: 1y, min_count: 12)
• Test retention policy

https://opensearch.org/docs/latest/opensearch/snapshots/sm-api