[lib] Migrate DeleteEntry/RestoreEntry notifTexts to use EntityText
Summary: Depends on D6576
Test Plan: Generated DeleteEntry and RestoreEntry messages on a web client in a chat with a different test user that is logged in on the iOS simulator. Background the iOS app and make sure the notif looks right
Reviewers: atul
Reviewed By: atul
Subscribers: tomek
Differential Revision: https://phab.comm.dev/D6577