FR #16136331 Search - results should be ordered with match on Title and then on SubTitle

- issue two queries instead of one. The first is for matching on the Title
and the second is for matching on the SubTitle (but use EXECEPT clause for
filtering out the potential dupe results that may be coming from the Title)
- use a MergeCursor for aggregating the two Cursor

Change-Id: I0ba4bb227dbd4a113348da8ed788ca7cded986fb