search: read user settings from database once in search path

Created by: keegancsmith

In a few places on our search path we called decodedViewerFinalSettings. This seemed to be often used to decide to use globbing or not. Each call in production seems to take roughly 25ms-40ms. We estimate that this will save about ~200ms on the critical path for Sourcegraph.com search requests.

This removes most places we call it by passing down the user settings in the searchResolver.

Co-Author: @eseliger