Some strings like console can be non-utf8

[poplexity]

We currently do not handle non-utf8 strings, we panic. But one example (console printing in ship data) can be non-utf8 and on Telos testnet there exists such a block that breaks decoding ship as a result. In that case, using Vec<u8> instead of String was a valid workaround, leaving the caller to convert to String and handle non-utf8.

This issue is to track the possibility of not panicing, or creating a way for the caller to specify the behavior they want (panic vs getting back a hex string).