Is your feature request related to a problem? Please describe.

Continuation of the issue #3324

In previous iterations we decomposed Snapshot manager into multiple implementations, depending of the storage backend.

But SnapshotStorageS3 is currently not implemented and not used.

Describe the solution you'd like

• Implement missing functions in SnapshotStorageS3
• Alter the settings, to allow explicitly select between local FS and S3
  Example:

storage:

  # Where to store snapshots
  snapshots_path: ./snapshots
  
  s3_config: 
    bucket: "s3://hello-world"
  
  snapshots_storage: "s3" | "local" # "local" - default

• Provide an integration test, which would run in CI and demonstrate that it is possible to create and recover from snapshot stored in s3 (deploy minio locally?) - similar to https://github.com/qdrant/qdrant/blob/3ad1528ebe04a45a4034f8f49d5458da01009487/tests/snapshots/snapshots-recovery.sh

Describe alternatives you've considered

Additional context

There are some notable previous attempts which might be helpful - #3430