Add crypto context errors (#8740)

Currently when connections to vault fail, client
perpetually retries this leads to assumptions that
the server has issues and masks the problem.

Re-purpose *crypto.Error* type to send appropriate
errors back to the client.

cmd/api-errors.go

@@ -1727,8 +1727,6 @@ func toAPIErrorCode(ctx context.Context, err error) (apiErr APIErrorCode) {
 		apiErr = ErrUnsupportedNotification
 	case BackendDown:
 		apiErr = ErrBackendDown
-	case crypto.Error:
-		apiErr = ErrObjectTampered
 	case ObjectNameTooLong:
 		apiErr = ErrKeyTooLongError
 	default:
@@ -1781,7 +1779,7 @@ func toAPIError(ctx context.Context, err error) APIError {
 			}
 		case crypto.Error:
 			apiErr = APIError{
-				Code:           "XKMSInternalError",
+				Code:           "XMinIOEncryptionError",
 				Description:    e.Error(),
 				HTTPStatusCode: http.StatusBadRequest,
 			}