[web] Add CryptoStore to persistConfig.whitelist

Summary:
We were previously excluding CryptoStore from redux-persist as we were working to avoid having to create a ton of migrations.

But now that we have primaryAccount/notificationAccount and primaryIdentityKeys/notificationIdentityKeys I think things are stable in the short term and we can start persisting.

Depends on D7081

Test Plan: Reload page and see that cryptoStore is included in REHYDRATE action:

Reviewers: ashoat, marcin, kamil

Reviewed By: ashoat

Subscribers: kamil, tomek

Differential Revision: https://phab.comm.dev/D7070