Searching for *sutta should work better

[khemarato]

Right now, if the user searches for e.g. "Paññāvimuttasutta" no results will come up because a) that's not how we store sutta names and b) we don't have every sutta in our DB.

This kind of search is surprisingly common though so could be handled better than just "no results."

A simple way to handle these would be to gently direct the user to the Sutta Name searcher tool somehow, perhaps by inserting a result for the tool's OBU entry.