clear all notifications after one is clicked - @$750000

[antonilol]

when i click one notification, only that one is removed. all the others stay.
every other app clears all notifications when the app is opened

[caydyan]

Submitted PR #741 for this bounty: #741

It clears all Sphinx notifications when a push notification opens the app, then consumes the chat_id extra so navigation is not processed twice.

Validation details are in the PR body.

Bounty payout address: bc1qev5ant33v5y89qqjvcf4mh9hlax5svqf5xd7gc