Write to temporary message storage from NotificationService

Summary: In this differential TemporaryMessagesStorage API is used in NotificationService to persist messages before they are written to SQLite.

Test Plan: In the debugger we can track execution to ensure no exception is thrown.

Reviewers: palys-swm

Reviewed By: palys-swm

Subscribers: ashoat, Adrian, atul, yayabosh

Differential Revision: https://phab.comm.dev/D4444