[lib] Extract a function that runs the migrations

Summary:
This function will be used when restoring a backup.

https://linear.app/comm/issue/ENG-7009/run-redux-migrations-after-the-backup-is-restored

Depends on D12014

Test Plan: Kill the app, add a migration, start the app and check the logs to see if the migration was run.

Reviewers: kamil, marcin, varun

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D12015