[lib] Set default state when wiping out a keyserver store

Summary:
Reset the keyserver state completely.

https://linear.app/comm/issue/ENG-7070/use-default-keyserver-state-in-wipekeyserverstore

Test Plan: Added a migration that always fails by returning handleReduxMigrationFailure on web and verify that rehydrate action sets the correct keyserver store.

Reviewers: kamil, inka, varun

Reviewed By: inka

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11440