Search statistics (/search/stats) are not updated when using template/fetch based search (eZContentFunctionCollection::fetchContentSearch()).

The call to eZSearchLog::addPhrase() exists only in the modules content/search and content/advancedsearch. It should be moved from there to eZSearch::search(), which is always used no matter the search method.

Steps to reproduce

• Search using module content/search
• Note that the search string shows up in /search/stats (OK)
• Search using template/fetch based search
• Note that the search string doesn't show up in /search/stats (BUG)