Update thread unread status from AppDelegate notifications callbacks on iOS

Summary: Update thread unread status from AppDelegate callbacks in response to rescinds

Test Plan: Comment-out encryption code in SQLiteQuery executor. Create two clients - A (web), B(mobile and web). Send message from A to B while mobile B is inactive. Open mobile B but do not read the message. Download the database from XCode. Kill mobile B, read message on web B and download SQLite database from XCode. Check that unread status in a thread the message was sent for changed from true to false.

Reviewers: palys-swm

Reviewed By: palys-swm

Subscribers: ashoat, Adrian, atul, yayabosh

Differential Revision: https://phab.comm.dev/D4238