Searches for numbers as well as words should treat numbers as strings

This prevents false-negatives when "ip version 6" is typed into the
search box, for instance.  It still allows "4 5 6" to find multiple
tickets by number.

Fixes I#22470.
Search subject as well as content if FTS is enabled

If indexed full-text searching is enabled, the simple search will search
for each value in both Subject and Content.
Update order on built TicketSQL from simple search in tests

Shifting from "subject" to "default" as aggregator term shifts it to
sorting before "status".
Merge branch '4.2/simple-search' into 4.2-trunk