readUint32BigEndian = decoder => {
  const uint = decoder.arr[decoder.pos + 3] + (decoder.arr[decoder.pos + 2] << 8) + (decoder.arr[decoder.pos + 1] << 16) + (decoder.arr[decoder.pos] << 24) >>> 0;
  decoder.pos += 4;
  return uint;
}
Read 4 bytes as unsigned integer in big endian order.
(most significant byte first)

@function
@param {Decoder} decoder
@return {number} An unsigned integer.