ARIFetch Fails on String Conversion

[helje5]

When ARIFetch receives a full read-buffer (4096 bytes), it sometimes stops. This is because the read() might end within an UTF-8 sequence (the UTF-8 decoding will fail and the non-optional withCString will just abort).

Solution: I think we need to check the buffer some bytes backwards for an UTF-8 marker, and then concatenate the results until something valid is constructed.
Or for the demo, we just build one big byte buffer, and then log it.