xhtml_style: don't allow google translate
Some users have been using google chrome builtin translation system with ERP5 back office (xhtml style), but the way google translation changes the DOM sometimes break ERP5 interface. This also have data privacy issue as this translation is done on google servers.
https://www.w3.org/International/questions/qa-translate-flag recommends using translate=no but the approach of the meta tag might be preferable for our case as it prevents sending the page content to translation service.