Reduce the total number of calls to getCallsign()
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