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/admin-handlers.go

@@ -1010,6 +1010,50 @@ func toAdminAPIErr(ctx context.Context, err error) APIError {
 				Description:    err.Error(),
 				HTTPStatusCode: http.StatusConflict,
 			}
+
+		// Tier admin API errors
+		case errors.Is(err, madmin.ErrTierNameEmpty):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierNameEmpty",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
+		case errors.Is(err, madmin.ErrTierInvalidConfig):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierInvalidConfig",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
+		case errors.Is(err, madmin.ErrTierInvalidConfigVersion):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierInvalidConfigVersion",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
+		case errors.Is(err, madmin.ErrTierTypeUnsupported):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierTypeUnsupported",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
+		case errors.Is(err, errTierBackendInUse):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierBackendInUse",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusConflict,
+			}
+		case errors.Is(err, errTierInsufficientCreds):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierInsufficientCreds",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
+		case errIsTierPermError(err):
+			apiErr = APIError{
+				Code:           "XMinioAdminTierInsufficientPermissions",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
 		default:
 			apiErr = errorCodes.ToAPIErrWithErr(toAdminAPIErrCode(ctx, err), err)
 		}