[web] Factor out handleReduxMigrationFailure

Summary:
In a later diff I want to call this from another file, and need to extract it in order to avoid an import cycle.

Pulling persistWhitelist in as well to avoid an import cycle.

Depends on D11883

Test Plan: Flow, and the testing done elsewhere in the stack

Reviewers: ginsu

Reviewed By: ginsu

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D11884