toUtf8 function
Should be called to get utf8 from it's hex representation
Implementation
String toUtf8(String hexString) {
ArgumentError.checkNotNull(hexString);
var bufferValue = hex.decode(
padToEven(stripHexPrefix(hexString).replaceAll(RegExp('^0+|0+\$'), '')));
return utf8.decode(bufferValue);
}