[lib] Replace LegacyRawThreadInfos with RawThreadInfos where simple in shared/updates
Summary:
Continuation of D10243.
NOTE: CI is expected to fail. I got to a point in my local environment where all flow issues were resolved, but based on earlier fedback in the stack I'm breaking them down so things are easier to review.. even if that means that intermediate steps fail.
Depends on D10243
Test Plan: CI/flow/etc.
Reviewers: ashoat, ginsu, rohan, tomek
Reviewed By: ginsu
Differential Revision: https://phab.comm.dev/D10268