Add support for bucket encryption feature (#8890)

- pkg/bucket/encryption provides support for handling bucket 
  encryption configuration
- changes under cmd/ provide support for AES256 algorithm only

Co-Authored-By: Poorna  <poornas@users.noreply.github.com>
Co-authored-by: Harshavardhana <harsha@minio.io>

cmd/api-errors.go

@@ -96,6 +96,7 @@ const (
 	ErrNoSuchBucket
 	ErrNoSuchBucketPolicy
 	ErrNoSuchBucketLifecycle
+	ErrNoSuchBucketSSEConfig
 	ErrNoSuchKey
 	ErrNoSuchUpload
 	ErrNoSuchVersion
@@ -487,6 +488,11 @@ var errorCodes = errorCodeMap{
 		Description:    "The bucket lifecycle configuration does not exist",
 		HTTPStatusCode: http.StatusNotFound,
 	},
+	ErrNoSuchBucketSSEConfig: {
+		Code:           "ServerSideEncryptionConfigurationNotFoundError",
+		Description:    "The server side encryption configuration was not found",
+		HTTPStatusCode: http.StatusNotFound,
+	},
 	ErrNoSuchKey: {
 		Code:           "NoSuchKey",
 		Description:    "The specified key does not exist.",
@@ -1719,6 +1725,8 @@ func toAPIErrorCode(ctx context.Context, err error) (apiErr APIErrorCode) {
 		apiErr = ErrNoSuchBucketPolicy
 	case BucketLifecycleNotFound:
 		apiErr = ErrNoSuchBucketLifecycle
+	case BucketSSEConfigNotFound:
+		apiErr = ErrNoSuchBucketSSEConfig
 	case *event.ErrInvalidEventName:
 		apiErr = ErrEventNotification
 	case *event.ErrInvalidARN: