Summary: Ref T4245. Before doing any hard work here, we can dramatically reduce the number of things that make calls to `getCallsign()` to make navigating things easier. Almost all of them only care about a monogram, URI, or display name. Test Plan: - Searched for `r uniquename` in jump nav. - Ran `bin/repository reparse --change rXXXyyyyy --trace`, observed query against bad commit table. - Ran `bin/search index rXXXyyyy --trace --force`, observed proper title when indexing commit. - Browed repository list, saw proper `rXXX` and appropriate link targets. - Mentioned `rXXX` in Remarkup, got a link to the right place. Reviewers: chad Reviewed By: chad Maniphest Tasks: T4245 Differential Revision: https://secure.phabricator.com/D14923