AssemblyScript has special methods for raw UTF8 bytes

So probably you could use `String.fromUTF8` instead this?
https://github.com/nearprotocol/assemblyscript-bson/blob/master/assembly/decoder.ts#L98

[link to String.fromUTF8](https://github.com/AssemblyScript/assemblyscript/blob/master/std/assembly/string.ts#L499)
[link to String#toUTF8](https://github.com/AssemblyScript/assemblyscript/blob/master/std/assembly/string.ts#L542)