Ensure that Java NBT uses "Modified UTF-8"

NBT in Minecraft Java is implemented with Java's [DataInput.readUTF(String)](https://docs.oracle.com/javase/8/docs/api/java/io/DataInput.html#readUTF--), and DataInput/Output represent strings with [Modified UTF-8](https://docs.oracle.com/javase/8/docs/api/java/io/DataInput.html#modified-utf-8) which is slightly different than standard UTF-8 for 0x00 and higher codepoints