message: fix QR code black box 2
diff: import BarcodeFormat from '../../../core/BarcodeFormat';
  import MultiFormatReader from '../../../core/MultiFormatReader';
  import AbstractBlackBoxSpec from '../common/AbstractBlackBox';
  -import { TextDecoder } from '@sinonjs/text-encoding';
  +import { TextDecoder, TextEncoder } from '@sinonjs/text-encoding';
  import StringEncoding from '../../../core/util/StringEncoding';
  StringEncoding.customDecoder = (b, e) => new TextDecoder(e, { NONSTANDARD_allowLegacyEncoding: true }).decode(b);
  +StringEncoding.customEncoder = (b, e) => new TextEncoder(e, { NONSTANDARD_allowLegacyEncoding: true }).encode(b);
  /**
  * @author Sean Owen
  