SVGHMI: i18n: ensure langs always appea in same order, and add two variables that are updated automatically when selecting a new language : lang_name and lang_code. Also fixed i18n startup, prevent wrong lang numer to crash loading.

<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema" URI_location="LOCAL://">
  <TargetType/>
</BeremizRoot>