[lib] Add a function for sanitizing the state on identity actions

Summary:
issue: ENG-6424
We want to reset the state to default on identity login / logout / delete account. We want to do it in one place, to reduce the risk of accidentally not clearing some state, and leaking data.
We want to have a "white list" of fields that are not supposed to be wiped. For example commServicesAccessToken, loadingStatuses, notifPermissionAlertInfo, lifecycleState etc.

Test Plan: ran the provided test

Reviewers: michal, kamil, ginsu, ashoat

Reviewed By: ashoat

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10801