Fix i18n in desktop containment
Review Request #123387 - Created April 16, 2015 and submitted
This adds 36 messages of which many were translatable before 5.3, but then became untranslatable probably when code bases were unified.
Translators can probably get their previous translations either automatically from obsolete messages at the end of the po file or manually from translation memory.
Sorry that I noticed this only now. :/
Tested extraction locally, did a quick translation update and checked that previously untranslated context menu entries now displayed as translated.