[Fix] Content types are not translated when displaying results of tags search

See forum: http://forum.joomla.org/viewtopic.php?f=711&t=863342&p=3233840#p3233840

>The string used is:
PLG_SEARCH_TAGS_ITEM_TAGGED_WITH="%s tagged with: %s"
the code used is
$new_item->section = JText::sprintf('PLG_SEARCH_TAGS_ITEM_TAGGED_WITH', $item->content_type_title, $row->title);

>Therefore the "Article" comes from the "$item->content_type_title" variable.
We have no lang string for each content-type, therefore it is NOT translated in Joomla.

To test, tag with the same tag a few items: article, category, weblink, etc.
Set debug Language on in Global Configuration
In Frontend, search for the Tag.
You will get something like this (`**Article**` shows a word is translated)
You also can change language for Frontend: you will always get the content_type title of the table row untranslated i.e hardcoded.
![beforethepatch](https://cloud.githubusercontent.com/assets/869724/4843894/f34ef7b2-6036-11e4-99c2-c92f661d3790.png)

Patch and test again in English
you will get:
![afterthepatch](https://cloud.githubusercontent.com/assets/869724/4843896/f9d7058e-6036-11e4-9105-4639243750d8.png)


IMPORTANT: although this solves the issue for core, it does not for 3rd party extensions using content_types