[web] Ensure that [primary/notification]IdentityPublicKeys are set in TraditionalLoginForm

Summary:
Ensure that primaryIdentityPublicKeys and notificationIdentityPublicKeys are set before enabling TraditionalLoginForm. Also pass both keypairs to user-actions:logIn(...), but pull them out from restLogInInfo to ensure we don't break keyserver request input validation.

Depends on D6880

Test Plan: Still able to log in to account from both web and native.

Reviewers: ashoat, tomek, marcin

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D6881