public String readNextAsciiString() throws IOException {
        String s = readAsciiString(currentIndex);
        currentIndex+=(s.length()+1);
        return s;
    }
Reads the Ascii string at the current index and then increments the current
index by the length of the Ascii string that was found. This method
expects the string to be null-terminated.
@return the null-terminated Ascii string at the current index
@exception IOException if an I/O error occurs
GPL/DMG/src/dmg/java/mobiledevices/dmg/ghidra/GBinaryReader.java