Part of https://linear.app/comm/issue/ENG-6366/rename-minimallyencodedrawthreadinfo-to-rawthreadinfo
I obviously don't want to make a separate diff for every function I modify in thread-utils, but figured it made sense to make this its own diff since there are corresponding changes to thread-settings-modal at callsite.
This also removes a bit of branching.
Depends on D10645