UTF-16 parsing in ndef looks untested and broken

[krzk]

UTF-16 (and maybe UTF-8 as well) parsing in ndef looks untested and broken. See @krzk work in progress:

• https://lore.kernel.org/linux-nfc/20210710033859.3989-15-krzysztof.kozlowski@canonical.com/ (the commit is not correct and requires further fixing)
• https://github.com/krzk/neard/tree/krzk/utf8-utf16 (and commits: krzk@b3e471e krzk@51bca34 )