Missing support for UTF-8 strings

[tomazs]

We have a few developer fields that can contain non ASCIII values. And with using Garmin's SDK for mobile app, these strings get encoded as UTF8. UTF8 is also specified in the spec - https://developer.garmin.com/fit/protocol/

Unfortunately this library decodes these strings as Unicode (and not UTF8). See

fit-decoder/src/fit2json.js

Line 172 in c5139c5

return String.fromCharCode(...result);