[native] Add a migration that moves entries to SQLite

Summary:
This migration saves the entries in SQLite

Depends on D12152

https://linear.app/comm/issue/ENG-3486/move-entrystore-to-sqlite

Test Plan: Killed a keyserver, opened the app - checked the logs, and verified that the migration was run. If the migration hasn't moved the entries successfully, there would be an alert reporting store inconsistencies.

Reviewers: kamil, marcin

Reviewed By: marcin

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D12157