Some basic fixups for search

[ChrisPenner]

Overview

Paul was getting some weird search results within the project:

This PR improves matching based on the final search segment a bit. It's still not as good as the main term search, ideally we'll switch over project search to use that mechanism but that's a more time intensive ordeal, so this is just a short-term patch for now.

Implementation notes

• Fix a bug in the infix-pattern matcher so the LIKE queries work as expected
• use the entire last segment of a dot-separated search when doing exact matching on last segment
• Return the name that matched in the results rather than the 'best name'

Test coverage

Transcripts and local testing.