R1:ff1bfb64dd56

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…