Support for remote tier management (#12090)

With this change, MinIO's ILM supports transitioning objects to a remote tier.
This change includes support for Azure Blob Storage, AWS S3 compatible object
storage incl. MinIO and Google Cloud Storage as remote tier storage backends.

Some new additions include:

 - Admin APIs remote tier configuration management

 - Simple journal to track remote objects to be 'collected'
   This is used by object API handlers which 'mutate' object versions by
   overwriting/replacing content (Put/CopyObject) or removing the version
   itself (e.g DeleteObjectVersion).

 - Rework of previous ILM transition to fit the new model
   In the new model, a storage class (a.k.a remote tier) is defined by the
   'remote' object storage type (one of s3, azure, GCS), bucket name and a
   prefix.

* Fixed bugs, review comments, and more unit-tests

- Leverage inline small object feature
- Migrate legacy objects to the latest object format before transitioning
- Fix restore to particular version if specified
- Extend SharedDataDirCount to handle transitioned and restored objects
- Restore-object should accept version-id for version-suspended bucket (#12091)
- Check if remote tier creds have sufficient permissions
- Bonus minor fixes to existing error messages

Co-authored-by: Poorna Krishnamoorthy <poorna@minio.io>
Co-authored-by: Krishna Srinivas <krishna@minio.io>
Signed-off-by: Harshavardhana <harsha@minio.io>

cmd/object-api-utils.go

@@ -45,7 +45,6 @@ import (
 	"github.com/minio/minio/cmd/crypto"
 	xhttp "github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
-	"github.com/minio/minio/pkg/bucket/lifecycle"
 	"github.com/minio/minio/pkg/hash"
 	"github.com/minio/minio/pkg/ioutil"
 	"github.com/minio/minio/pkg/trie"
@@ -614,8 +613,8 @@ func NewGetObjectReader(rs *HTTPRangeSpec, oi ObjectInfo, opts ObjectOptions, cl
 		return nil, 0, 0, err
 	}
 
-	// if object is encrypted, transition content without decrypting.
-	if opts.TransitionStatus == lifecycle.TransitionPending && (isEncrypted || isCompressed) {
+	// if object is encrypted and it is a restore request, fetch content without decrypting.
+	if opts.Transition.RestoreRequest != nil {
 		isEncrypted = false
 		isCompressed = false
 	}