[lib][native] Introduce deviceID parameter to initial notif message function

Summary: This function will be used in connection handlers which are aware of the device id. This diff doesn't change any logic - the actual changes will be handled as a part of preparing notifs for multiple keyservers.

Test Plan: Check if encrypted notifs are received by iOS device.

Reviewers: varun, marcin, kamil

Reviewed By: varun, marcin, kamil

Subscribers: kamil, ashoat

Differential Revision: https://phab.comm.dev/D10660