Search highlighter uses full-text string instead of createHighlights function

[svandaalen]

The new search highlighter uses the full-text string as written by the user, meaning that the highlighter will try to highlight whatever the user writes in the full-text search input field. This causes problems when the user starts using ES query string queries like suriano AND che because the highlighter will try to highlight the entire "suriano AND che" string.

A previous iteration of the search highlighter used the createHighlights function which extracted the search highlights from the ES results, meaning that ES has already interpreted the ES query string query. The new search highlighter should use the same (or similar) function.