StringParser not specifying encoding to use

Class `flink.types.parser.StringParser` has javadocs indicating that contents are expected to be Ascii, similar to `StringValueParser`. That makes sense, but when constructing actual instance, no encoding is specified; on line 66 f.ex:

this.result = new String(bytes, startPos+1, i - startPos - 2);

which leads to using whatever default platform encoding is. If contents really are always Ascii (would not count on that as parser is used from CSV reader), not a big deal, but it can lead to the usual Latin-1-VS-UTF-8 issues.

So I think that encoding should be explicitly specified, whatever is to be used: javadocs claim ascii, so could be "us-ascii", but could well be UTF-8 or even ISO-8859-1.