fix copying elements with non-latin content like comment element, or
variables with description in non-latin character set

before any non-latin text was converted after copying to strings like 'Это...'

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Python xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.w3.org/2001/XMLSchema" xsi:schemaLocation="python_xsd.xsd">
<![CDATA[]]>
</Python>