[lib] Update convertRawThreadInfoToClientDBThreadInfo to handle RawThreadInfo

Summary:
Basically modify function to pull out minimallyEncoded field before converting to ClientDBThreadInfo representation. This is fine because all of the columns in the SQLite database are compatible with the new "shape" of the data here.

Unfortunately, we can't do this as easily with convertClientDBThreadInfoToRawThreadInfo because it's used as part of migrations so we don't want to change the behavior of those migrations for users upgrading from an older version. Will have to create a "legacy" version of that function so migration functionality is retained.

Depends on D10197

Test Plan: CI/flow/etc

Reviewers: ashoat, ginsu, tomek, rohan

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D10198