[native] Rip LegacyThreadInfo out of native/chat

Summary:
Update all props and callbacks being "drilled" to ThreadInfo from LegacyThreadInfo.

We're now down to 61 usages of LegacyThreadInfo from 700+

Depends on D10139

Test Plan: CI/flow/etc.

Reviewers: ashoat, ginsu, tomek, rohan

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D10140