[native] Reintroduce createUpdateDBOpsForThreadStoreThreadInfos for new RawThreadInfo encoding

Summary:
Discussed in D11057, but we want to "freeze" the previous implementation of createUpdateDBOpsForThreadStoreThreadInfos in place to support old migrations while re-introducing a new version that only handles MinimallyEncoded -> MinimallyEncoded migrations. We will only have MinimallyEncoded -> MinimallyEncoded migrations in the future, so IMO it doesn't make sense to clutter up createUpdateDBOpsForThreadStoreThreadInfos to be able to handle

• LegacyRawThreadInfos => LegacyRawThreadInfos
• LegacyRawThreadInfos => MinimallyEncodedRawThreadInfos
• MinimallyEncodedRawThreadInfos => MinimallyEncodedRawThreadInfos

It also lets us avoid having to go back and test some of the old migrations when we tweak createUpdateDBOpsForThreadStoreThreadInfos.

Depends on D11057

Test Plan: This gets consumed for the first time in the upcoming specialRoles migration where it will be tested implicitly.

Reviewers: ginsu, tomek, kamil, michal

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11095